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Supermassive black holes have been found at the heart of most galaxies but understanding how they have formed has eluded astronomers for some time. One of the most popular theories suggests they merge over and over again to form larger black holes. A recent discovery may support this however the pair of supermassive black holes are orbiting 24 light years apart and measure an incredible 28 billion solar masses making it the heaviest ever seen. 

A black hole is a region of space within which the escape velocity is greater than the speed of light. Ok so the definition is a little more complicated than that but that will suffice for now. They are objects that have undergone gravitational collapse with their largest versions, the supermassive black holes which have a mass from hundreds of thousands to billions of times that of the Sun. It’s now thought that nearly every massive galaxy has a supermassive black hole at its core. 

Galaxy mergers seem to be common with many examples visible in the sky like the classic Whirlpool Galaxy in the northern hemisphere. When they do, it is thought their black holes can form a binary pair. Ultimately it is believed they merge however this has never been observed. A paper that was recently published in the Astrophysical Journal and authored by a team led by Tirth Surti explores this process. 

Magnetic fields mapped within the Whirlpool Galaxy. Credit: NASA, SOFIA science team, ESA, STScI

One such binary black hole system exists inside elliptical galaxy B2 0402+379 (a catchy name if ever there was one) and the team analysed its data from the Gemini North Telescope. It’s possible to resolve this binary system so the team could study it in more detail than any before. The black holes are separated by only 24 light years and data shows the system to be an impressive 28 billion times the mass of the Sun. 

The team studied the stars in the vicinity of the black holes using the Gemini Multi-Object Spectrograph (GMOS) so they could determine their velocity. Measuring the velocity enabled the team to determine the mass of the black hole binary pair but also supports the theory that the mass of the black hole plays a role in delaying and even stalling their merging!

It turns out that B2 0402+379 is a so called ‘fossil cluster’ which means that it is the result of the merging of an entire cluster of galaxies. After such mergers, the black holes don’t crash head on into each other, instead they tend to swing by each other and fall into a bound orbit around a common centre of gravity. As they swing by each other, energy is transferred from the black holes to the nearby stars. As they lose energy, they get closer and closer and in the case of stellar mass black holes, they merge. This never seems to happen with supermassive binary black holes. 

In the case of binary black holes with large mass, the team propose that a huge number of stars would be needed in the vicinity to slow them sufficiently to bring them close enough to merge. Instead, the black holes seem to have ejected nearly all the matter from the region leaving it local mass low enough that the pair’s orbits are not able to slow and merge. Whether this is the ultimate fate and the binary pair are destined to orbit forever or eventually merge is still yet to be determined. If they do merge however, it is likely that the resultant gravitational wave will be far more powerful, potentially hundreds of millions of times more than a stellar mass merger. 

Source :

A black hole is a region of space within which the escape velocity is greater than the speed of light. Ok so the definition is a little more complicated than that but that will suffice for now. They are objects that have undergone gravitational collapse with their largest versions, the supermassive black holes which have a mass from hundreds of thousands to billions of times that of the Sun. It’s now thought that nearly every massive galaxy has a supermassive black hole at its core. 

Galaxy mergers seem to be common with many examples visible in the sky like the classic Whirlpool Galaxy in the northern hemisphere. When they do, it is thought their black holes can form a binary pair. Ultimately it is believed they merge however this has never been observed. A paper that was recently published in the Astrophysical Journal and authored by a team led by Tirth Surti explores this process. 

One such binary black hole system exists inside elliptical galaxy B2 0402+379 (a catchy name if ever there was one) and the team analysed its data from the Gemini North Telescope. It’s possible to resolve this binary system so the team could study it in more detail than any before. The black holes are separated by only 24 light years and data shows the system to be an impressive 28 billion times the mass of the Sun. 

The team studied the stars in the vicinity of the black holes using the Gemini Multi-Object Spectrograph (GMOS) so they could determine their velocity. Measuring the velocity enabled the team to determine the mass of the black hole binary pair but also supports the theory that the mass of the black hole plays a role in delaying and even stalling their merging!

It turns out that B2 0402+379 is a so called ‘fossil cluster’ which means that it is the result of the merging of an entire cluster of galaxies. After such mergers, the black holes don’t crash head on into each other, instead they tend to swing by each other and fall into a bound orbit around a common centre of gravity. As they swing by each other, energy is transferred from the black holes to the nearby stars. As they lose energy, they get closer and closer and in the case of stellar mass black holes, they merge. This never seems to happen with supermassive binary black holes. 

In the case of binary black holes with large mass, the team propose that a huge number of stars would be needed in the vicinity to slow them sufficiently to bring them close enough to merge. Instead, the black holes seem to have ejected nearly all the matter from the region leaving it local mass low enough that the pair’s orbits are not able to slow and merge. Whether this is the ultimate fate and the binary pair are destined to orbit forever or eventually merge is still yet to be determined. If they do merge however, it is likely that the resultant gravitational wave will be far more powerful, potentially hundreds of millions of times more than a stellar mass merger. 

Source : Astronomers Measure Heaviest Black Hole Pair Ever Found

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Packing to go to space is a lot like getting ready for a plane ride with only a carry-on bag. You have to maximize the use of the space in your bag at the same time you want to make sure you have what you need. That’s the challenge astronauts face in the upcoming Artemis moon missions. So, NASA held a competition to figure out the best and most innovative ways to store cargo for the missions.

The Lunar Gateway Cargo Packing and Storing challenge asked members of the public to come up with good ways to pack materials in the limited space on the lunar Gateway that will be orbiting the Moon. The idea inspired some 90 participants from 35 countries to step up and show off their packing skills. It also helped that there were cash prizes for the winners. Everybody submitted written solutions and 3D computer models to show what could be done for astronauts who would need easy, quick access to their cargo.

The design parameters had to take into account storing the cargo delivered to the gateway by the logistics module. The most efficient space design would allow astronauts to access the cargo easily in the module, which will also be their food and supply storage room, plus a place to store trash. So, given everything that needs to be placed there efficiently, the idea was to maximize volume and minimize mass.

And the Winner is…

The best design came from Austria, made by designer Kriso Leinfellner. It’s called QASIS, short for Quick Access Storage in Space. It’s a fairly straightforward method of stacking and packing that maximizes the amount of space the cargo takes up. It also proposes lightweight storage structures and does not rely on motors or batteries to power cranes or other equipment to move the boxes.
Leinfellner won $3,000.00 for this design.

Four other prizes of amounts ranging from $2,000.00 to $250.00 were awarded to winners from Turkey, Brazil, Nigeria, and Germany. They took into account launch and orbital conditions, and several specified manual and/or automated systems to move cargo around for access.

Packing Space for Artemis and the Gateway

The Artemis program will have multiple missions, and the logistics will vary with each crew or cargo trip. So, the “packing space” challenge used the following scenario. A crew of four launches in the Orion capsule on top of an SLS rocket on a three-week mission to the Gateway. Two crew members will then travel on to the Moon to spend a week of exploration and science experiments. Before the crew arrives at Gateway, it will have already been visited by an uncrewed Logistics module packed with supplies. It will be there waiting for the astronauts to arrive about a week later.

The lunar module on approach to the Moon and Gateway station. Courtesy NASA and SpaceX.

Just to make things more complicated, there won’t be a lot of space available at the Gateway. NASA’s plans show that the station will be about the size of a one-bedroom apartment, so a fraction of the size of the International Space Station. Once the astronauts get there, they’ll move in, using an internal system to help them stow the supplies. The contest asked entrants to design that stowage system.

Artemis Mission Overview

The Artemis mission is an ambitious long-range plan for lunar exploration and eventual habitation. It focuses primarily on scientific exploration of the lunar surface. Lessons learned on the Moon will translate to longer-term missions to Mars. The Gateway part of the mission is crucial. It provides an orbiting space station on the Moon, which will function as a transfer point and supply depot. There are Deep Space Logistics project offices at the Johnson Space Center in Houston. However, the Kennedy Space Center is responsible for leading the commercial supply chain. That team solicits and procures bids for cargo transport, equipment acquisition, and consumable supplies for the mission—both in the gateway and on the lunar surface.

The complex supply logistics of the Artemis mission. Courtesy NASA. (Click to enlarge.)

Why such a complex chain? It’s a complex mission, involving the construction of the Gateway, which requires transport of materials to the “construction site” in lunar orbit. It’s going to be there for several years, so long-term viability is important. It serves as the link to the lunar surface and so it will become the staging area for materials needed on the Moon for bases and installations.

Everything for Artemis and its Gateway has to withstand the rigors of launch, orbital insertion at the Moon, and use/reuse by the astronauts who will be passing through. Five Artemis missions will happen. Others are still in the proposal stages. Artemis 1 flew in 2022 as an uncrewed test flight. It “practiced” putting Orion into lunar orbit and then brought the capsule back to Earth. Artemis 2 could fly in late 2025, although that will likely slip. It will be the first crewed test flight and will do orbital testing around Earth and the Moon. Artemis 3 will be the first crewed lunar landing, bringing a diverse set of astronauts to the newly built lunar Gateway and then to the Moon. After that, Artemis 4 and 5 will fly (dates still to be determined) and will take astronauts to the gateway and lunar surface for further explorations.

For More Information

NASA Names Winners in Lunar Gateway Packing and Storing Challenge
Gateway Logistics

The post What’s the Best Way to Pack for Space? appeared first on Universe Today.

Nearly 5 billion years ago a region of gas gravitationally collapsed within a vast molecular cloud. At the center of the region, the Sun began to form, while around it formed a protoplanetary disk of gas and dust out of which Earth and the other planets of the solar system would form. We know this is how the solar system began because we have observed this process in systems throughout the galaxy. But there are details of the process we still don’t understand, such as why gas planets are relatively rare in our system.

Our solar system only has four gas planets. The rest are the rocky worlds of the inner solar system. Then there are countless asteroids and the icy worlds of Pluto and the outer solar system. Most of them don’t contain a lot of volatile gasses, which is strange because early protoplanetary disks typically have a hundred times more gas than dust. So how does a gassy disk evolve into a planetary system of mostly rock? The answer can be found in recent observations of a young system known as TCha.

The general idea is that during the later stage of planetary formation the central star increases in brightness. The light from the star then drives winds within the disk which clears any remaining gas from the system. While this model can explain the type of planetary systems we observe, the process hasn’t been observed directly. That is, until this recent study.

How photon pressure can clear a planetary system of gas. Credit: Naman S. Bajaj, et al

TCha is a system in the late stages of planetary formation. Earlier observations found it has a large dust gap within the disk with a radius of more than 30 AU, indicating that much of the early material has already cleared. So in this new study, the team used observations from the James Webb Space Telescope (JWST) to measure the spectral lines of ionized argon and neon. This study is the first observation of a particular argon line, Ar III.

The team made two main discoveries. The first is based on the ionizing energy levels, which indicates that argon is mostly ionized by extreme ultraviolet light, while neon is mostly ionized by X-rays. The second is that both gases are rapidly expanding away from the star, as seen by the Doppler shift of the spectral lines. Together these discoveries show that the gases are part of a stellar wind driven by high-energy photons.

Based on the observations, the team estimates that the TCha disk is losing about a Moon’s worth of mass every year, which is fast enough to clear the planetary disks in agreement with observations of planetary systems. While there are many details of planetary evolution we still don’t understand, this study supports the standard model.

Reference: Naman S. Bajaj, et al. “JWST MIRI MRS Observations of T Cha: Discovery of a Spatially Resolved Disk Wind.” The Astronomical Journal 167 (2024): 127.

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Unlocking the mysteries of the early Universe is one of the JWST’s primary endeavours. Finding and examining some of the first galaxies is an important part of its work. One of the Universe’s first galaxies is extraordinarily luminous, and researchers have wondered why. It looks like the JWST has found the answer.

The galaxy at issue is named GN-z11, and it existed when the Universe was less than half a billion years old. The Hubble first spotted it in 2016, with help from the Spitzer Space Telescope. At the time, it was the most distant, ancient galaxy ever spotted. In the paper announcing the discovery, the authors wrote, “GN-z11 is luminous and young, yet moderately massive, implying a rapid build-up of stellar mass in the past.”

They also wrote that “Future facilities will be able to find the progenitors of such galaxies at higher redshift and probe the cosmic epoch at the beginning of reionization.” Now that the JWST is deep into its mission, that’s exactly where we find ourselves. It also took a closer look at GN-z11.

The discoverers suggested that the galaxy’s high luminosity could be caused by an active galactic nucleus (AGN) but weren’t certain. New research based on JWST observations shows that they were right. It looks like the galaxy’s luminosity comes from a supermassive black hole (SMBH) in the galaxy’s centre, lighting it up as it actively accretes matter. One of the telltale signs is a gas clump near the SMBH.

“We found extremely dense gas that is common in the vicinity of supermassive black holes accreting gas,” explained principal investigator Roberto Maiolino of the Cavendish Laboratory and the Kavli Institute of Cosmology at the University of Cambridge in the United Kingdom. “These were the first clear signatures that GN-z11 is hosting a black hole that is gobbling matter.”

Scientists know that the region near an SMBH is extremely hot and that gas clumps form near there. The hole’s powerful gravity creates a swirling accretion disk of material near it, and the material in the disk can be accelerated to relativistic speeds. At those speeds, the molecules collide and generate friction. That generates heat that can reach a temperature of millions of degrees. The extreme heat drives gas outward at extremely high speeds, but it can also drive the gas to form dense clumps like the ones JWST found at GN-z11.

The clump lacks metallicity, so it’s likely primordial in nature, uncontaminated by heavier elements that would only later be created by successive generations of stars.

This graphic shows a clump of pristine helium near GN-z11. The full spectrum shows no evidence of other elements and so suggests that the helium clump is fairly pristine, made almost entirely of hydrogen and helium gas left over from the Big Bang. It’s uncontaminated by heavier elements produced by stars. Theory and simulations in the vicinity of particularly massive galaxies from these epochs predict that there should be pockets of pristine gas surviving in the halo, and these may collapse and form Population III star clusters. Image Credit: NASA, ESA, CSA, Ralf Crawford (STScI) CC BY 4.0 INT

We’ve never seen the Universe’s first stars, the Population III stars. But as the very first stars, they formed from hydrogen and helium, all that was available at the time. Finding those first stars is an important goal in astronomy, so finding these similarly pristine clumps is important. The gas clumps found by JWST are also made only of hydrogen and helium, so they could be precursors to the formation of Population III stars.

“The fact that we don’t see anything else beyond helium suggests that this clump must be fairly pristine,” said Maiolino. “This is something that was expected by theory and simulations in the vicinity of particularly massive galaxies from these epochs – that there should be pockets of pristine gas surviving in the halo, and these may collapse and form Population III star clusters.”

Population III stars were the Universe’s first stars and contained only hydrogen and helium. They were extremely massive, luminous stars, and many of them exploded as supernovae. Image Credit: DALL-E

Two more pieces of evidence support the black hole hypothesis. Accreting black holes produce ionized chemical elements, and the JWST found evidence of them. The powerful space telescope also detected high winds with velocities of 800 to 1000 km/s-1 near the black hole, another result of the processes involved in actively accreting black holes. (Some rare starburst galaxies can also produce powerful winds, but they show less ionization.)

“Webb’s NIRCam (Near-Infrared Camera) has revealed an extended component, tracing the host galaxy, and a central, compact source whose colours are consistent with those of an accretion disc surrounding a black hole,” said investigator Hannah Übler, also of the Cavendish Laboratory and the Kavli Institute.

There doesn’t seem to be much doubt that GN-z11 has a black hole and its accretion disk in its center. But the fact that this galaxy’s extreme luminosity is powered by a black hole raises interesting questions. It has to do with black hole seeds and the Eddington rate.

Scientists think that black holes in the early Universe could have formed differently than stellar mass black holes, which form when a star collapses under its own gravity. Instead, these ancient black holes formed from seeds, collections of matter massive enough to collapse directly into black holes. There could be large, intermediate, and small black hole seeds. The researchers behind these results write that the black hole is “… accreting at about five times the Eddington rate. These properties are consistent with both heavy seeds scenarios and scenarios considering intermediate and light seeds experiencing episodic super-Eddington phases.”

The Eddington rate is the rate at which a black hole has to accrete matter to reach the Eddington limit. The Eddington limit is the maximum luminosity an object can reach while its outward force of radiation is equal to its inward force of gravity.

But black holes can exceed the Eddington limit during super-Eddington episodes. Those episodes may be able to explain the rapid assembly of supermassive black holes (SMBHs) in the Universe’s first billion years. Super-Eddington episodes are associated with radiatively inefficient accretion and are often accompanied by powerful outflowing winds and jets.

If the researchers are correct, then they’ve figured out the mystery behind this extremely ancient and extremely luminous galaxy. “Our finding explains the high luminosity of GN-z11…,” the authors write.

Note: The research on the pristine gas clump in GN-z11’s halo has been accepted for publication in Astronomy & Astrophysics. The results of the study of GN-z11’s black hole were published in the journal Nature on 17 January 2024

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If the periodic table listed the elements in order of their importance to life, then oxygen might bully its way to the top. Without oxygen, Earth’s complex life likely would not exist. So when scientists detect oxygen on another world, they turn their attention to it.

During Juno’s ambitious mission to the Jovian system, it performed some flybys and observations of some of the Jovian moons. One of those moons, Europa, is a prime target in the search for life because of its subsurface ocean. It became an even more important target when scientists realized that the icy moon was producing oxygen.

We can’t see it with our organic eyes, but Europa’s surface is under bombardment. Not by rocky objects, which do strike occasionally, but by energetic particles. Europa is in a perilous position so close to giant Jupiter, and the planet makes its presence known.

Jupiter’s enormously powerful magnetic field sends a constant stream of charged particles at Europa. The much smaller moon has no defence. When those particles strike Europa’s icy surface, they split water molecules apart and produce hydrogen and oxygen.

“Europa is like an ice ball slowly losing its water in a flowing stream. Except, in this case, the stream is a fluid of ionized particles swept around Jupiter by its extraordinary magnetic field,” said JADE scientist Jamey Szalay from Princeton University in New Jersey. “When these ionized particles impact Europa, they break up the water-ice molecule by molecule on the surface to produce hydrogen and oxygen. In a way, the entire ice shell is being continuously eroded by waves of charged particles washing up upon it.”

Szalay is the lead author of new research published in Nature Astronomy. The research is “Oxygen production from dissociation of Europa’s water-ice surface.”

One of Juno’s instruments is JADE, the Jovian Auroral Distributions Experiment. JADE can detect and measure ions and electrons, primarily in Jupiter’s aurora and magnetosphere regions. In September of 2022, Juno came to within 354 km (220 miles) of Europa. During that flyby, JADE measured the hydrogen and oxygen ions created by the particles bombarding the moon.

Scientists have known about the bombardment and the hydrogen and oxygen since the days of the Galileo mission. But Juno’s updated instruments are providing new insights into the phenomenon.

“Back when NASA’s Galileo mission flew by Europa, it opened our eyes to the complex and dynamic interaction Europa has with its environment. Juno brought a new capability to directly measure the composition of charged particles shed from Europa’s atmosphere, and we couldn’t wait to further peek behind the curtain of this exciting water world,” said Szalay. “But what we didn’t realize is that Juno’s observations would give us such a tight constraint on the amount of oxygen produced in Europa’s icy surface.”

Knowing oxygen is being produced and knowing how much are two different things. It’s possible that some of this oxygen is making its way back down through the ice into the warm, salty ocean that probably exists there. If enough oxygen makes its way into the water, it’s one more factor in favour of life.

An unending stream of charged particles from Jupiter strikes Europa’s icy surface, splitting frozen water molecules into oxygen and hydrogen molecules. This has been going on for billions of years. If some of that oxygen has worked its way into the moon’s subsurface ocean, then it boosts the chances that life could exist there. NASA/JPL-Caltech/SWRI/PU

This new research is refining scientists’ understanding of how much oxygen is being produced on Europa. While previous research into Europa’s oxygen was based on models, these results are based on Juno’s measurements.

“Europa’s atmospheric composition had never been directly sampled, and model-derived oxygen production estimates ranged over several orders of magnitude,” the authors write in their research. “Here, we report direct observations of H2+ and O2+ pickup ions from the dissociation of Europa’s water-ice surface and confirm these species are primary atmospheric constituents.”

Previous research arrived at disparate estimates of the icy moon’s oxygen production. Some said only a few kilograms of oxygen are produced per second, while others range as high as 1000 kilograms per second. But thanks to Juno’s direct sampling, this research puts the amount of oxygen produced on Europa at 12 kg (26 lbs) per second.

Quantifying the amount of oxygen produced is a critical part of understanding the moon and its environment. It’s also a critical part of understanding the moon’s potential habitability. But for the oxygen to do any life-enabling work, it has to find its way through the ice into the ocean. Does it?

When charged particles strike Europa’s surface, they split water molecules apart. The lighter hydrogen floats away into space, but the oxygen stays behind. If the oxygen somehow makes its way to the ocean, it could provide chemical energy for microbial life. Image Credit: NASA

When the particles dissociate the water molecules into hydrogen and oxygen, the hydrogen is so light that it escapes Europa’s gravity. But the oxygen is heavier. It sticks around and forms part of Europa’s thin, tenuous atmosphere, making it one of only a handful of Solar System moons to have an atmosphere and one of an even smaller number of worlds with oxygen.

Multiple studies show that the released oxygen doesn’t all remain in the atmosphere. Research published in 2022 shows that oxygen can make it through the ice and down into the ocean. It’s all because of the moon’s ‘chaos terrain.’

Image of Europa’s ice shell, taken by the Galileo spacecraft, of fractured “chaos terrain.” In this terrain, cracks, ridges, and plains are all jumbled together. Scientists think that this terrain allows surface oxygen to penetrate the ice and make its way into the subsurface ocean. Image Credit: NASA/JPL-Caltech

Europa’s chaos terrain covers about one-quarter of the moon’s surface. Its exact cause is uncertain but is likely related to heating and melting taking place underneath it. The chaos terrain might sit over the top of lakes of melted brine contained in the moon’s icy shell. These lakes aren’t directly connected to the ocean but can drain into them.

Some of these lakes may be only 3 km (1.9 miles) below the surface, according to the 2022 research. The authors say that the surface oxygen can mix with the water in these lakes, which then drains into the ocean. If that’s the case, then the ocean may contain enough oxygen to support microbial life.

This figure from the 2022 research helps explain how oxygen could make it through the ice and into Europa’s ocean. Some of the O2 is released into the moon’s atmosphere, but most of it returns to the icy regolith and is trapped in bubbles. The bubbles are the dominant near-surface reservoir for oxidants. Over thousands of years, the bubbles can make their way down to the ocean. Image Credit: Hesse et al. 2022.

“Our research puts this process into the realm of the possible,” said the lead author of the 2022 research. “It provides a solution to what is considered one of the outstanding problems of the habitability of the Europa subsurface ocean.”

We don’t know if this process takes place on Europa yet. But the oxygen has to go somewhere, so the whole idea is very intriguing.

These new findings are all a result of Juno’s extended mission. The extended mission sent Juno through Europa’s torus, the ring-shaped cloud of ions around the moon so that JADE could take these important measurements.

This figure from the research illustrates Juno’s path through Europa’s torus during the spacecraft’s extended mission. The inset diagram shows how charged particles split H2O molecules into hydrogen and oxygen. The hydrogen escapes into space, but the heavier oxygen sinks back to the surface. Image Credit: Szalay et al. 2024.

“Our ability to fly close to the Galilean satellites during our extended mission allowed us to start tackling a breadth of science, including some unique opportunities to contribute to the investigation of Europa’s habitability,” said Scott Bolton, Juno’s principal investigator from the Southwest Research Institute in San Antonio. “And we’re not done yet. More moon flybys and the first exploration of Jupiter’s close ring and polar atmosphere are yet to come.”

Juno will keep gathering data until its extended mission ends in 2025 or until the spacecraft stops functioning. The extreme radiation at Jupiter is slowly eroding the spacecraft’s electronics, though they’re inside a protective titanium vault.

The Europa Clipper will be the next mission to the Jovian system. It’s focused on Europa and should tell us more about the moon’s oxygen and potential habitability when it reaches the system in 2030.

The post Juno Measures How Much Oxygen is Being Produced by Europa appeared first on Universe Today.

We know that there are thousands of exoplanets out there, with many millions more waiting to be discovered. But the vast majority of exoplanets are simply uninhabitable. For the few that may be habitable, we can only determine if they are by examining their atmospheres. LIFE, the Large Interferometer for Exoplanets, can help.

The search for biosignatures on potentially habitable exoplanets is heating up. The JWST has successfully gathered some atmospheric spectra from exoplanet atmospheres, but it has a lot of other jobs to do and observing time is in high demand. A planned space telescope named LIFE is dedicated to finding exoplanet biosignatures, and recently, researchers gave it a test: can it detect Earth’s biosignatures?

As an interferometer, LIFE is made up of five separate telescopes that will work in unison to expand the telescope’s working size. LIFE is being developed by ETH Zurich (Federal Institute of Technology Zurich) in Switzerland. LIFE will observe in mid-infrared, where the spectral lines from the important bioindicative chemicals ozone, methane, and nitrous oxide can be found.

LIFE will be located at Lagrange Point 2, about 1.5 million km (1 million miles) away, where the JWST is also located. From that location, it’ll observe a list of exoplanet targets in hopes of finding biosignatures. “Our goal is to detect chemical compounds in the light spectrum that hint at life on the exoplanets,” explained Sascha Quanz, Professor for Exoplanets and Habitability at ETH Zurich, who is leading the LIFE initiative.

A transmission spectrum of the hot gas giant exoplanet WASP-39 b, captured by JWST’s Near-Infrared Spectrograph (NIRSpec) on July 10, 2022, reveals the first definitive evidence for carbon dioxide in the atmosphere of a planet outside the Solar System. It was an exciting result, but only a taste of what we’ll learn from LIFE. Credit: NASA, ESA, CSA, and L. Hustak (STScI). Science: The JWST Transiting Exoplanet Community Early Release Science Team

LIFE is still only a concept, and researchers wanted to test its performance. Since it hasn’t been built yet, a team of researchers used Earth’s atmosphere as a test case. They treated Earth as if it were an exoplanet and tested LIFE’s methods against Earth’s known atmospheric spectrum in different conditions. They used a tool called LIFEsim to work with the data. Researchers often use simulated data to test mission capabilities, but in this case, they used real data.

Their results are published in The Astronomical Journal. The research is titled “Large Interferometer For Exoplanets (LIFE). XII. The Detectability of Capstone Biosignatures in the Mid-infrared—Sniffing Exoplanetary Laughing Gas and Methylated Halogens.” The lead author is Dr. Daniel Angerhausen, an Astrophysicist and Astrobiologist at ETH in Zürich.

In a real-world scenario, Earth would be just a distant, nearly impossible to discern speck. All LIFE would see is the planet’s atmospheric spectrum, which would change over time depending on what views the telescope captured and, critically, for how long it observed it.

These spectra would be gathered over time, and that leads to an important question: how would the observational geometry and seasonal variations affect LIFE’s observations?

Fortunately for the research team, we have ample observations of Earth for them to work with. The researchers worked with three different observational geometries: two views from the poles and one from the equatorial region. From those three viewpoints, they worked with atmospheric data from January and July, which accounts for the largest seasonal variations.

Though planetary atmospheres can be extremely complex, astrobiologists focus on certain aspects to reveal a planet’s potential to host life. Of particular interest are the chemicals N20, CH3Cl, and CH3Br (nitrous oxide, chloromethane, and bromomethane), all of which can be produced biogenically. “We use a set of scenarios derived from chemical kinetics models that simulate the atmospheric response of varied levels of biogenic production of N2O, CH3Cl, and CH3Br in O2-rich terrestrial planet atmospheres to produce forward models for our LIFEsim observation simulator software,” the authors write.

In particular, the researchers wanted to know if LIFE will be able to detect CO2, water, ozone and methane on planet Earth from about 30 light years away. These are signs of a temperate, life-supporting world—especially ozone and methane, which are produced by life on Earth—so if LIFE can detect biological chemistry on Earth in this way, it can detect it on other worlds.

LIFE was able to detect CO2, water, ozone and methane on Earth. It also detected some surface conditions that indicate liquid water. Intriguingly, LIFE’s results didn’t depend on which angle Earth is viewed from. This is important since we don’t know what angles LIFE will be observing exoplanets from.

Seasonal fluctuations are the other issue, and they weren’t as easy to observe. But fortunately, it looks like that won’t be a limiting factor. “Even if atmospheric seasonality is not easily observed, our study demonstrates that next-generation space missions can assess whether nearby temperate terrestrial exoplanets are habitable or even inhabited,” said Quanz.

However, detecting the desired chemicals isn’t enough. The critical piece is how long it takes. Building a space interferometer that detected these chemicals but took too much time to do it wouldn’t be practical or effective. “We use the results to derive observation times needed for the detection of these scenarios and apply them to define science requirements for the mission,” the research team writes in their paper.

To paint a larger picture of LIFE’s observing times, the researchers developed a list of targets. They created a “… distance distribution of HZ planets with radii between 0.5 and 1.5 Earth radii around M and FGK-type stars within 20 pc of the Sun that are detectable with LIFE.” The data for these targets comes from NASA and from other previous research.

This figure from the study illustrates the list of targets. The panel on the left shows planets around M-dwarf stars by distance. It shows the number of predicted planet targets for three different habitable zones: optimistic, conservative, and exo-Earth candidates. The panel on the right shows the same but for F, G, and K-type stars. Image Credit: Angerhausen et al. 2024.

The results show that only a few days are needed for some targets, while for others, it could take up to 100 days to detect relevant abundances.

What the team calls “golden targets” are the easiest to observe. Planets in Proxima Centauri are an example of these types of targets. Only a few days of observation are needed for these planets. It’ll take about ten days of observations with LIFE to observe “certain standard scenarios such as temperate, terrestrial planets around M star hosts at five pc,” the researchers write. The most challenging cases that are still feasible are exoplanets that are Earth twins about 5 parsecs away. According to the results, LIFE needs between about 50 – 100 days of observing to detect the biosignatures.

LIFE is still just a potential mission at this point. It’s not the first proposed mission that would be solely focused on exoplanet habitability. In 2023, NASA proposed the Habitable Worlds Observatory (HWO). Its goal is to directly image at least 25 potentially habitable worlds and then search for biosignatures in their atmospheres.

But, according to the authors, their results show that LIFE is the best option.

“If there are late-type star exoplanetary systems in the solar neighbourhood with planets that exhibit global biospheres producing N2O and CH3X signals, LIFE will be the best-suited future mission to systematically search for and eventually detect them,” they conclude.

The post The LIFE Telescope Passed its First Test: It Detected Biosignatures on Earth. appeared first on Universe Today.

Stars shape their solar systems. It’s true of ours, and it’s true of others. But for some massive stars, their power to shape still-forming systems is fateful and final.

In their youth, stars are surrounded by a rotating mass of gas and dust called a protoplanetary disk. Planets form in these disks, and the process can take millions of years. But stars have different masses and different radiation outputs that affect how planets form, or if they form at all.

New research examines how the powerful UV radiation from massive stars affects planet formation in disks. The research article is “A far-ultraviolet–driven photoevaporation flow observed in a protoplanetary disk.” It’s published in the journal Science, and the lead author is Olivier Berne from the Institute for Research in Astrophysics and Planetology, University of Toulouse, France.

The research looks at large stars in their first million years of life, when they’re not only young but extremely luminous. The researchers focused on several stars in the Orion Nebula and its stellar nurseries. The stars are at least ten times more massive than the Sun and are 10,000 times more luminous. What effect does their luminosity and all that radiation have on disks where planets form?

These powerful young stars emit high levels of Far-Ultraviolet (FUV) radiation, which has the power to remove mass from planet-forming disks. This power extends beyond their own immediate surroundings into the disks around neighbouring low-mass stars.

“Most low-mass stars form in stellar clusters that also contain massive stars, which are sources of far ultraviolet (FUV) radiation,” the researchers explain. “Theoretical models predict that this FUV radiation produces photodissociation regions (PDRs) on the surfaces of protoplanetary disks around low-mass stars, which affects planet formation within the disks.” The PDRs can span several hundred astronomical units (AU).

The researchers examined one protoplanetary disk that’s within range of energetic, high-mass stars residing in the Trapezium Cluster in the heart of the Orion Nebula. The five brightest stars in that cluster range from 15 to 30 solar masses, making them prime candidates to study PDRs in neighbouring planet-forming disks. The Orion Bar PDR is an often-studied and prototypical PDR.

The Orion Nebula. The Trapezium Cluster is above and to the right of the three stars in Orion’s Belt in this image. The stars in Trapezium are mostly responsible for illuminating Orion, and their powerful FUV energy can strip gas from the protoplanetary disks surrounding lower-mass stars nearby. Image Credit: NASA, ESA, M. Robberto (Space Telescope Science Institute/ESA) and the Hubble Space Telescope Orion Treasury Project Team, Public domain, via Wikimedia Commons

The disk in the image, d203-506, is being bombarded by intense FUV radiation from the massive Trapezium stars. The FUV radiation is dispersing matter in the disk, inhibiting planet formation. According to the research, it’s impossible for a Jupiter-mass planet to form in this disk because the radiation is stripping matter away.

This figure from the research has an optical image from Hubble on the left. On the right is a JWST NIR image of the same region, including a zoomed-in view of the d203-506 disk. The dotted line marks a feature named the Orion Bar PDR. On the upper right of the Bar, the gas is fully ionized, and on the lower left, the gas is neutral. The smaller inset image of the disk shows a bright spot where jets from the embedded star are sending material out into space. Image Credit: Berne et al. 2024.

“Planet formation is limited by processes that remove mass from the disk, such as photoevaporation,” the authors write. “This occurs when the upper layers of protoplanetary disks are heated by x-ray or ultraviolet photons.” Once heated, the gas exceeds the escape velocity of the disk, and the gas leaves the system.

After the radiation drives mass out of the disk, it collects in a diffuse envelope around the disk.

This schematic from the research illustrates some of the forces involved in the d203-506 planet-forming disk. Features like the bright spot and the jets are visible but unlabelled in the JWST images preceding this one. The brown arrows show gas being driven out of the disk by the FUV radiation, which produces the tan envelope around the disk. The orange outline is the dissociation front. Image Credit: Berne et al. 2024.

The powerful FUV radiation dissociates molecular hydrogen into atomic hydrogen. The PDR marks the transition between molecular and atomic hydrogen. As the hydrogen is converted into atomic hydrogen, it becomes warmer, and the heating helps drive the photoevaporation of the hydrogen.

When the star inside the affected disk is more massive, that helps restrict the loss of hydrogen from the disk. Its gravity can help the disk retain matter, making it available for planet formation.

This all plays out relatively quickly in a disk. In the d203-506 disk, the star is only about 0.3 solar masses. The researchers write that in only about 0.13 million years, enough material will be removed from the disk to prohibit the formation of a Jupiter-mass planet. “This is faster than even very early planet formation,” the researchers write.

But powerful FUV radiation and the PDRs they produce do more than just inhibit the formation of gas giants. They shape other aspects of the future solar system as well.

“The effect affects the disk mass, radius, and lifetime, its chemical evolution, and the growth and migration of any planets forming within the disk,” the authors explain.

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As if the Mars Perseverance Rover and Ingenuity Drone were not exciting enough then the next step in this audacious mission takes it to a whole new level. Mars Sample Return Mission is to follow along, collect and return the samples collected by Perseverance back to Earth. However the status of Mars Sample Return is uncertain as engineers are still working on technology to retrieve the samples. The current challenge is the gripper arm that will collect the samples and stow them safely and securely before transportation without damaging them. 

Mars, known as the “Red Planet,” is the fourth planet from the Sun.  It’s named after the Roman god of war and has fascinated humans for centuries. The distinctive rusty-red colour and mysterious terrain has over the years, led many to believe Mars was inhabited by aliens. Exploration has shown us though that Mars is a barren landscape that is home to Olympus Mons, the largest volcano, and Valles Marineris, the deepest canyon, in the solar system. 

Featured Image: True-color image of the Red Planet taken on October 10, 2014, by India’s Mars Orbiter mission from 76,000 kilometers (47,224 miles) away. (Credit: ISRO/ISSDC/Justin Cowart) (This file is licensed under the Creative Commons Attribution 2.0 Generic license.)

Viking 1 was the first spacecraft to visit Mars, successfully touching down on 20 July 1976 in the Chryse Planitia region. It comprised an orbiter and lander both of which were equipped with high resolution cameras to undertake a detailed examination of the Martian surface and atmosphere. A host of other spacecraft have visited Mars since then, most recently the Perseverance rover which carried with it the Ingenuity aircraft. 

One of the mission objectives of Perseverance was to collect samples from Martian rocks and soil using the onboard drill. The samples were collected during a process known as ‘sample caching’ and then stored in tubes before being deposited on the surface for later collection. It’s a procedure that has never been undertaken before but set the foundations for future missions to collect and transport the samples back to Earth. Perseverance has been busy, there are now 23 titanium tubes sat on the Martian surface just waiting to be delivered back to Earth.  

Mars Perseverence rover sent back this image of its parking spot during Mars Solar Conjunction. Courtesy NASA/JPL-Caltech

Enter Mars Sample Return mission, a joint NASA and ESA project that is planned to collect the tubes and bring them home for study. Engineers are now working on a prototype robotic arm that will collect the tubes from the surface. It uses a grip with two ‘fingers’ to pickup the hermetically sealed tubes from various angles and positions. There is a mechanism that ensures enough grip to pickup but not damage the tube or its contents which are Martian samples about the size of a piece of classroom chalk. It can even collect them direct from the rover itself. 

As with all space missions, backup plans must always be considered. In the case of the the Sample Return mission the backup is likely to be two helicopters based on the Ingenuity design that can collect the tubes and deposit them in front of the lander for collection. An audacious mission perhaps but we will have to wait until 2028 to see the lander on Mars and until 2033 for the samples to be returned to Earth.

Source : Grip on Mars

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Nothing is immortal. Everything has a finite existence, including the stars themselves. How a star dies depends on several factors, most importantly their mass. For the Sun, this means that in several billion years it will swell to a red giant as it churns through the last of its nuclear fuel. The core that remains will then collapse to become a white dwarf. Of course, the Sun is home to several planets, including Earth. What of their fate? What of ours? According to a recent study, the Sun’s death might consume Earth in the end.

There are three main ideas as to how planetary systems end. One is that planets can be cast off into interstellar space to become rogue planets. As a star loses its outer layers, its decreased gravitational pull may allow planets to escape their orbit. Another possibility is that planets can survive the red giant stage of a star and remain in orbit. We have found several planets orbiting white dwarfs, so we know this is a possibility. The third option is that during the red giant stage a planet is dragged down by stellar gas, spiraling ever inward until it collides with its star and is consumed. It’s this option that is the focus of the new study.

The study is based upon a white dwarf known as WD 0816-310, which is what’s known as a “polluted” white dwarf. This means its spectrum shows the presence of metallic elements that aren’t the product of the white dwarf itself. These contaminants could be caused by dust backfalling onto the white dwarf at the end of the red giant stage, or by asteroids or planets colliding with the star. Since heavier elements would tend to sink into the white dwarf and not be visible in the atmospheric spectra, the presence of these metals gives astronomers a way to study the time since accretion and look at whether it happened gradually or all at once.

In this study, the team found evidence of metallic accretion in a short geological period. What’s more, they found that the presence of metals was not evenly distributed across the star as you would expect from dust or a scattering of small asteroids. Instead, they found a localized region of metals, as a kind of metallic scar caused by a single impact. Based on their study, the team estimated that the impact was caused by an object at least as big as Vesta, which is the second largest asteroid in the solar system, with a diameter of about 500 km.

Given the diversity of exoplanetary systems, it is likely that all three scenarios can occur. We know of rogue planets, we see dead stars with exoplanets, and now we see the scars of planetary impacts upon a white dwarf. One of these fates will be Earth’s. For now, only time knows which outcome it will be.

Reference: Bagnulo, Stefano, et al. “Discovery of magnetically guided metal accretion onto a polluted white dwarf.” The Astrophysical Journal Letters 963.1 (2024): L22.

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Just about every day we here on Earth get a breathtaking picture of Mars’s terrain sent back by a rover. But, the view from space can be pretty amazing, too. The Mars Reconnaissance Orbiter (MRO) just sent back a thought-provoking picture of Curiosity as it makes its way up a steep ridge on Mount Sharp.

The rover is a tiny black dot in the center of the image, which gives a good feeling for what MRO’s HiRISE camera accomplished. For scale, the rover is about the size of a dinner table, sitting in a region of alternating dark and light bands of material on the Red Planet.

NASA’s Curiosity Mars rover appears as a dark speck in this image captured from directly overhead by the agency’s Mars Reconnaissance Orbiter, or MRO. Credit: NASA/JPL-Caltech/University of Arizona Where’s Curiosity?

The Curiosity rover is exploring an ancient ridge on the side of Mount Sharp, which is the peak of a crater on Mars. It’s sitting on the side of a feature called Gediz Vallis Ridge, and the terrains and materials preserve a record of what things were like when water last flowed there. That happened about three billion years ago. The force of the flow brought significant amounts of rocks and debris through the region. They piled up to form the ridge. So, much of what you see here is the desiccated remains of that flooding.

Debris flows are pretty common here on Earth, particularly in the aftermath of floods, volcanic eruptions, tsunamis, and other actions. We can see them wherever material floods through a region or down a slope. In a flood-based flow, the speed of the water combines with gravity and the degree of slope to send material rushing across the surface. A debris flow can also be a dry landslide, and those can occur pretty much anywhere on Earth where the conditions are right. Another type of debris flow comes from volcanic activity. That occurs when material erupts from a volcano, or when earthquakes combined with an eruption collapse material into the side of the mountain. That results in what’s called a “lahar”. Folks in North America might recall the Mount St. Helens eruption in 1980; it resulted in several lahars that buried parts of the surrounding terrain.

Now that scientists see similar-seeming regions on Mars, they want to know several things. How did they form? Were they created by the same processes that make them on Earth? And, how long ago did they begin to form? Curiosity and Perseverance and other rovers and landers have been sent to Mars to help answer those questions.

Understanding the Debris Ridge

Did any of these actions happen on Mars? The evidence is pretty strong, which is why Gediz Vallis itself is a major exploration goal for the rover. It’s a canyon that stretches across 9 kilometers of the Martian surface and is carved about 140 meters deep. Gediz was likely carved by so-called “fluvial” activity (meaning flowing action) in the beginning. Later floods deposited a variety of fine-grained sands and rocks. Over time, winds have blown a lot of that material away, leaving behind protected pockets of materials left behind by the flooding. The size of the rocks tells something about the speed of the flows that deposited all the material. Geological studies of those rocks will reveal their mineral compositions, including their exposure to water over time.

The Gediz Vallis ridge resulted from the action of water pushing rocks and dirt around to build it up over time. Planetary scientists now need to figure out the sequence of events that created it. The clues lie in the scattered rocks in the region and the surrounding terrain. Mount Sharp itself (formally known as Aeolis Mons), is about 5 kilometers high and is, essentially, a stack of layered sedimentary rocks. As Curiosity makes its way up the mountain, it explores younger and younger materials.

NASA’s Curiosity captured this 360-degree panorama while parked below Gediz Vallis Ridge (seen at right), a formation that preserves a record of one of the last wet periods seen on this part of Mars. After previous attempts, the rover finally reached the ridge on its fourth try. Credits: NASA/JPL-Caltech/MSSS. Curiosity’s Mission at Gediz

To put all this on a larger scale, Mount Sharp is the central peak of Gale Crater. It formed some 3.5 to 3.8 billion years ago from an impact. As time went by, water flooded the crater several times. It flowed out and eventually disappeared as Mars’s climate changed it to the dusty desert we see today.

Winds also played a role in filling the crater with dust and sand deposits. This so-called aeolian activity also helped carve out Mount Sharp. This history of wind- and water-based deposition and erosion made Gale Crater a very attractive place to explore. That’s why Curiosity was sent there and continues its journey up Mount Sharp.

For More Information

HiRISE Spots Curiosity Driving Toward Upper Gediz Vallis
Curiosity Views Gediz Vallis Ridge
The Gediz Vallis Inverted Channel: Evidence for Late-state Flow in Gale Crater, Mars?

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Gamma-ray bursts (GRBs) are one of the most powerful phenomena in the Universe and something that astronomers have been studying furiously to learn more about their origins. In recent years, astronomers have set new records for the most powerful GRB ever observed – this includes GRB 190114C, observed by the Hubble Space Telescope in 2019, and GRB 221009A, detected by the Gemini South telescope in 2022. The same is true for high-energy cosmic rays that originate from within the Milky Way, whose origins are still not fully understood.

In a recent study, members of China’s Large High Altitude Air Shower Observatory (LHAASO) Collaboration discovered a massive gamma-ray burst (designated GRB 221009A) in the Cygnus star-forming region that was more powerful than 10 peta-electronvolts (PeV, 1PeV=1015eV), over ten times the average. In addition to being the brightest GRB studied to date, the team was able to precisely measure the energy spectrum of the burst, making this the first time astronomers have traced cosmic rays with this energy level back to their source.

The team was led by Prof. Cao Zhen, a professor at the Institute of High Energy Physics of the Chinese Academy of Sciences (CAS-IHEP), and included CAS members Dr. Gao Chuandong, Dr. Li Cong, Prof. Liu Ruoyu, and Prof. Yang Ruizhi. Their results were described in a paper titled “An ultrahigh-energy gamma-ray bubble powered by a super PeVatron,” which appeared on November 15th in Science Bulletin. The LHAASO Collaboration comprises over 280 members representing 32 astrophysics research institutions worldwide.

The Large High-Altitude Air Shower Observatory (LHAASO) is a composite array made up of 5216 electromagnetic particle detectors, 1188 muon detectors, a 78,000-square-meter water Cherenkov detector array, and 18 wide-angle Cherenkov telescopes. The observatory is located at a height of 4,410 meters (14468.5 ft) on Mount Haizi in Sichuan Province, China, and is dedicated to studying cosmic rays. When cosmic rays reach Earth’s atmosphere, they create “showers” of secondary particles, some of which reach the surface.

The origin of cosmic rays is one of the most important issues in astrophysics today. In the past few decades, astronomers have detected three high-energy GRBs at a peak of about one petaelectronvolts (PeVs) – one quadrillion electronvolts (1015eV) – in their energy spectrum. Scientists believe cosmic rays with energy beneath this level come from astrophysical sources within the Milky Way (like supernovae). This peak energy represents a limit for cosmic rays, which generally take the form of protons accelerated to near-light speed.

However, the origins of cosmic rays in the region of a few petaelectronvolts remain one of the more intriguing mysteries in astrophysics today. Based on data acquired by LHAASO, the Collaboration team discovered a giant ultra-high-energy gamma-ray bubble in the Cygnus X cluster (the largest star-forming region in the Solar neighborhood) located roughly 2.4 billion light-years from Earth. Photons detected inside the structure showed a maximum energy reading of 2.5 PeV, while those ejected showed energy values of up to 20 PeV – the highest ever recorded.

From this, the team inferred the presence of a massive cosmic ray accelerator near the center of the Bubble, which they believe to be the massive star cluster Cygnus OB2 within Cygnus X. This cluster is composed of many young massive stars, including blue-white O-type giants and B-type blue giants, with surface temperatures of over 35,000 and 15,000 °C (63,000 and 27,000 °F), respectively. These stars generate radiation pressure hundreds to millions of times that of the Sun that blows stellar surface material away, creating solar winds that move at speeds of up to thousands of kilometers per second.

GRB 221009A: looking back through time. Credit: ESA

Collisions between this wind and the ISM create high-energy gamma rays and the ideal environment for efficient particle acceleration. These findings represent the highest-energy cosmic rays detected to date and the first cosmic ray accelerator ever observed. The team’s observations also indicated that the accelerator significantly increases the cosmic ray density in the surrounding ISM, greatly exceeding the average level of cosmic rays in the Milky Way. Lastly, the measured background light intensity in the infrared band was much lower than expected, roughly 40% of what cosmological models suggest.

These observations challenge the standard model of GRB afterglows and could lead astronomers to rethink current models of galaxy formation and evolution. Similarly, it could provide crucial information for testing Special Relativity (SR) and the possibility that Dark Matter is composed of axions. Professor Elena Amato, an astrophysicist with the Italian National Institute for Astrophysics (INAF), indicated that these results “not only impacts our understanding of diffuse emission, but has also very relevant consequences on our description of cosmic ray (CR) transport in the Galaxy.”

Further Reading: Chinese Academy of Sciences

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Before the end of this decade, NASA plans to return astronauts to the Moon for the first time since the Apollo Era. But this time, through the Artemis Program, it won’t be a “footprints and flags” affair. With other space agencies and commercial partners, the long-term aim is to create the infrastructure that will allow for a “sustained program of lunar exploration and development.” If all goes according to plan, multiple space agencies will have established bases around the South Pole-Aitken Basin, which will pave the way for lunar industries and tourism.

For humans to live, work, and conduct various activities on the Moon, strategies are needed to deal with all the hazards – not the least of which is lunar regolith (or “moondust”). As the Apollo astronauts learned, moondust is jagged, sticks to everything, and can cause significant wear on astronaut suits, equipment, vehicles, and health. In a new study by a team of Texas A&M engineers, regolith also poses a collision hazard when kicked up by rocket plumes. Given the many spacecraft and landers that will be delivering crews and cargo to the Moon in the near future, this is one hazard that merits close attention!

The study was conducted by Shah Akib Sarwar and Zohaib Hasnain, a Ph.D. Student and an Assistant Professor (respectively) with the J. Mike Walker ’66 Department of Mechanical Engineering at Texas A&M University. For their study, Sarwar and Hasnain investigated particle-particle collisions for lunar regolith using the “soft sphere” method, where Newton’s equations of motion and a contact force model are integrated to study how particles will collide and overlap. This sets it apart from the “hard sphere” method, which models particles in the context of fluids and solids.

Apollo 15 astronaut salutes next to the American flag in 1971. The Moon’s regolith or soil appears in various shades of gray. Credit: NASA

While lunar regolith ranges from tiny particles to large rocks, the main component of “Moondust” is fine, silicate minerals with an average size of 70 microns. These were created over billions of years as the airless Moon’s airless surface was struck by meteors and asteroids that pounded much of the lunar crust into a fine powder. The absence of an atmosphere also meant that erosion by wind and water (common here on Earth) was absent. Lastly, constant exposure to solar wind has left lunar regolith electrostatically charged, which means it adheres to anything it touches.

When the Apollo astronauts ventured to the Moon, they reported having problems with regolith that would stick to their suits and get tracked back into their lunar modules. Once inside their vehicles, it would adhere to everything and became a health hazard, causing eye irritation and respiratory difficulties. But with the Artemis missions on the horizon and the planned infrastructure it will entail, there’s the issue of how spacecraft (during take-off- and landing) will cause regolith to get kicked up in large quantities and accelerated to high speeds.

As Sarwar related to Universe Today via email, this is one of the key ways lunar regolith will be a major challenge for regular human activities on the Moon:

“During a retro-propulsive soft landing on the Moon, supersonic/hypersonic rocket exhaust plumes can eject a large quantity (108 – 1015 particles/m3 seen in Apollo missions) of loose regolith from the upper soil layer. Due to plume-generated forces – drag, lift, etc. – the ejecta can travel at very high speeds (up to 2 km/s). The spray can harm the spacecraft and nearby equipment. It can also block the view of the landing area, disrupt sensors, clog mechanical elements, and degrade optical surfaces or solar panels through contamination.”

Data acquired from the Apollo missions served as a touchstone for Sarwar and Hasnain, which included how ejecta from the exhaust plume from the Apollo 12 Lunar Module (LM) damaged the Surveyor 3 spacecraft, located 160 meters (525 ft) away. This uncrewed vehicle had been sent to explore the Mare Cognitum region in 1967 and characterize lunar soil in advance of crewed missions. Surveyor 3 was also used as a landing target site for Apollo 12 and was visited by astronauts Pete Conrad and Alan Bean in November 1969.

A look at the Apollo 12 landing site. Astronaut Alan Bean is shown working near the Modular Equipment Stowage Assembly (MESA) on the Apollo 12 Lunar Module (LM) during the mission’s first extravehicular activity (EVA) on Nov. 19, 1969. Credit: NASA.

The damage was mitigated by the fact that Surveyor 3 was sitting in a crater below the landing site of the Apollo 12 LM. Another example is the Apollo 15 mission that landed in the Hadley–Apennine region in 1971. During the LM’s descent, astronauts David R. Scott and James B. Irwin could not see the landing site because their exhaust plume had created a thick cloud of regolith above it. This forced the crew to select a new landing site on the rim of Béla, an elongated crater to the east of the region. The LM could not achieve a balanced footing at this site and tilted backward 11 degrees before stabilizing itself.

Research conducted since these missions took place led to the conclusion that the scattering was likely caused by collisions between regolith particles. As Sarwar indicated, these examples illustrate how disturbed regolith can become a hazard, especially where other spacecraft and facilities are positioned nearby:

“The above two examples from the Apollo-era were not severe enough to jeopardize mission success. But future Artemis (and CLPS) missions will take place on the lunar south pole, where the soil is assumed to be significantly more porous/weak than the equatorial and mid-latitude Apollo landing regions. Also, Artemis landers are expected to deliver much larger payloads than Apollo, and therefore require more thrust to slow down. As a result, deep cratering can happen (not seen in Apollo) due to rocket exhaust plumes and blow the regolith at much higher angles than those seen previously (~1-3 degrees above ground).”

In accordance with the long-term goals of the Artemis Program, NASA plans to build infrastructure around the southern polar region to allow for a “sustained program of lunar exploration and development.” This includes the Artemis Base Camp, consisting of a foundation surface habitat, a habitable mobility platform, a lunar terrain vehicle (LTV), and the Lunar Gateway in orbit. “As such, protecting humans, structures, or nearby spacecraft from the hazards of lunar regolith particles is of paramount concern,” said Sarwar.

Illustration of NASA astronauts on the lunar South Pole. Mission ideas we see today have at least some heritage from the early days of the Space Age. Credit: NASA

Similar research has shown how clouds of regolith caused by landing and take-off could also pose a hazard to the safe operation of the Lunar Gateway and lunar orbiters. These threats have driven considerable research into how lunar dust can be mitigated during future missions. As noted, Sarwar and Hasnain used the soft sphere method to evaluate the risks posed by particle-particle collisions:

“In this method, adjacent particles are allowed to overlap each other by a tiny amount, which is taken as an indirect measure of the deformation expected in a real particle-particle collision. This overlap value, along with relevant material properties of lunar regolith, are then used in a spring-dashpot-friction slider representation to calculate forces in each collision event. The inelasticity involved in a collision is varied from completely inelastic to highly elastic.

“Our results reveal that highly elastic collisions between relatively large regolith grains (~100 microns) cause a significant portion of them to eject at large angles (some can fly out at ~90 degrees). The rest of the grains are, however, contained in a small-angle region (<3 degrees) along the ground – which is in line with the visible regolith sheet observed during the Apollo missions.”

In terms of safeguards, Sarwar and Hasnain suggest that berms or fences around a landing zone are a way to mitigate ejecta sprays. However, as their research suggests, a certain percentage of regolith particles may scatter at large angles due to collisions, making berns or fencing insufficient. “A better solution for future Artemis missions would be to build a landing pad,” said Sarwar. “In this regard, a multi-organization team with personnel from both academia (including Dr. Hasnain) and industry is working on developing the in-Flight Alumina Spray Technique, or FAST landing pads.”

The FAST method envisions lunar landers equipped with alumina particles that are ejected during landing maneuvers. They are then liquefied by engine plumes to create molten aluminum on the lunar surface, which cools and solidifies to create a stable landing surface. NASA has also investigated how landing pads could be built using sintering technology, where regolith is blasted with microwaves to create molten ceramics that harden on contact with space. Another idea is to build landing pads with blast walls to contain ejected regolith, which the Texas-based construction company ICON included in their Lunar Lantern habitat concept.

Illustration of the in-Flight Alumina Spray Technique (FAST). Credit: Masten Space Systems

Alas, experimental investigations concerning lunar regolith are very difficult because lunar conditions are vastly different than those on Earth. This includes the lower gravity (roughly 16.5% of Earth’s), the vacuum environment, and the extreme temperature variations. Hence why researchers are forced to rely heavily on numerical modeling, which typically focuses on plume forces and largely ignores the role of particle collisions. But as Sanwar noted, their research offers valuable insight and illustrates why it is important to consider this often-overlooked phenomenon when planning future lunar missions:

“[However,] our research on particle collisions has shown that this is a very important phenomenon to consider for accurate regolith trajectory prediction and, therefore, must be included. There are still a lot of challenges remaining in this area, such as a lack of knowledge on regolith particle restitution coefficient (which determines energy loss in a collision), effects of regolith size distribution, implications of turbulent plumes etc. We hope to elucidate some of these uncertainties in the future and contribute towards a more comprehensive lunar PSI model for safer Artemis lunar landings.”

Further Reading: Acta Astronautica

The post New Study Addresses how Lunar Missions will Kick up Moondust. appeared first on Universe Today.

Scientists are discovering that more and more Solar System objects have warm oceans under icy shells. The moons Enceladus and Europa are the two most well-known, and others like Ganymede and Callisto probably have them too. Even the dwarf planet Ceres might have an ocean. But can any of them support life? That partly depends on the water temperature, which strongly influences the chemistry.

We’re likely to visit Europa in the coming years and find out for ourselves how warm its ocean is. Others on the list we may never visit. But we may not have to.

Researchers at Cornell University are figuring out how to determine the temperature of an icy world’s ocean by measuring the thickness of its ice shell and associated properties. They published their results in a research article in the journal JGR Planets. It’s titled “Ice-Ocean Interactions on Ocean Worlds Influence Ice Shell Topography,” and the lead author is Justin Lawrence, a visiting scholar at the Cornell Center for Astrophysics and Planetary Science. Lawrence is also a program manager at Honeybee Robotics, a subsidiary of Blue Origin that builds technologies for space exploration.

Their research is based on what’s called ice-pumping, a phenomenon observed under the ice in Antarctica.

“When ice is submerged, a melting and freezing exchange process termed the “ice pump” can affect ice composition, texture, and thickness,” the researchers write. “We find that ice pumping is likely beneath the ice shells of several ocean worlds in our solar system.”

Ice pumping is more commonly called thermohaline ice pumping, where thermo means heat and haline means basically the same thing as saline: salty. But whereas saline refers to fresh water, haline refers to ocean water.

On Earth, large-scale thermohaline ice pumping supplies heated water to the north and south polar regions. On a smaller scale, affects how much ice forms on the underside of an ice sheet since ice is formed from water containing no salt or very little salt. So, the salt from the ice-forming water is concentrated in the water under the ice. Since that salt-concentrated water is so close to the ice, the water under the ice is both higher in salt and colder because it’s close to the ice. That’s why the term thermohaline is used.

The high-salinity shelf water (HSSW) that forms under the ice is denser than the surrounding water and sinks. As it sinks, it then becomes warmer than the freezing point there since the water pressure lowers the freezing point. So now the HSSW is warmer and triggers melting on the underside of the ice shelf. Then, the HSSW mixes with lower-salinity meltwater to create colder, buoyant ice-shelf water (ISF.) The ISF upwells and forms soft ice called frazil ice on the underside of the ice shelf. The process can create ice layers hundreds of meters thick.

The critical part is where the ocean and the ice interact. The researchers say that if they can determine the ice thickness, they can constrain the water temperature from afar. The press release presenting the results calls this “conducting oceanography from space.”

This schematic from the study shows how thermohaline ice pump circulation works below a generalized ice shelf. (1) High salinity shelf water (HSSW) forms at the surface freezing point (Tf = ?1.9°C) as the brine rejected from sea ice growth mixes into the water column. (2) HSSW is dense relative to the surrounding seawater, so it sinks, and a portion circulates beneath the ice shelf to the grounding zone, where it is now warm compared to the pressure-depressed freezing point (positive thermal driving) and drives melting. (3) Fresh meltwater generated at the colder, in situ freezing point mixes with HSSW, generating fresher, colder, and relatively buoyant Ice Shelf Water (ISW). (4) ISW upwells, the freezing point increases and thermal driving commensurately decreases. With a sufficient pressure decrease, supercooling occurs and frazil ice forms, which can accumulate into hundreds of meters thick layers of marine ice at the ice shelf base. Credit: Journal of Geophysical Research: Planets (2024). DOI: 10.1029/2023JE008036

“Anywhere you have those dynamics, you would expect to have ice pumping,” Lawrence said. “You can predict what’s going on at the ice-ocean interface based on the topography—where the ice is thick or thin, and where it is freezing or melting.”

There’s uncertainty around which Solar System bodies have ice pumping and how close ice pumping on Earth is similar to other bodies. For example, if Europa’s ice shell is thicker than about 35 km (22 miles) and has low salt content, then there may be no ice pumping. “However, the majority of predictions for Europa’s ice shell thickness suggest that the interface falls in the marine regime, such that Earth’s ice shelves can serve as system analogs to inform European ice-ocean interactions,” the authors write in their research.

Ice pumping is probable on Ganymede and Titan, according to the authors, as long as bulk ocean salinity isn’t too low. On the other hand, Enceladus almost certainly has ice pumping. But the ice pumping on Enceladus is expected to be weaker, while at Europa, it’s expected to be much stronger.

Jupiter’s icy moon Europa likely has strong ice pumping very similar to the Ross Ice Shelf in Antarctica. Credits: NASA/JPL-Caltech/SETI Institute

What does it all add up to?

“If we can measure the thickness variation across these ice shells, then we’re able to get temperature constraints on the oceans, which there’s really no other way yet to do without drilling into them,” said Britney Schmidt, associate professor of astronomy and of Earth and atmospheric sciences in the College of Arts and Sciences and Cornell Engineering. “This gives us another tool for trying to figure out how these oceans work. And the big question is, are things living there, or could they?” Schmidt asks.

We can only answer that question incrementally right now. To do that, we need to understand the ice shell, the temperature, and how they’re connected to make progress.

“There’s a connection between the shape of the ice shell and the temperature in the ocean,” Schmidt said. “This is a new way to get more insight from ice shell measurements that we hope to be able to get for Europa and other worlds.”

Right now, estimates for Europa’s ice shell thickness range from 10 to 30 km (6 to 20 mi). For Enceladus, estimates range from 20 to 25 km (12 to 16 miles), though the south pole region’s ice is much thinner, only 1 to 5 km thick (1/2 mile to 3 miles.)

Oddly enough, the icy shells and underlying oceans on the Solar System’s icy worlds may be more similar to Earth than any other planets or moons. The interactions between ice and the ocean on Europa are very similar to what researchers see under Antarctica’s Ross Ice Shelf. In 2019, Schmidt and other researchers observed the underside of the shelf with the Icefin robot and observed ice pumping.

Another factor at play here is gravity. “Ice pumping scales with gravity and so may prove important to dynamics at the ice shell-ocean interfaces of other similarly massive ocean worlds such as Ganymede or Titan,” the authors explain. That’s one of the reasons that Enceladus is expected to have weaker ice pumping: its gravity is ten times weaker than Europa’s.

This study is important because it shows how ice pumping can occur on different ocean worlds in the Solar System, and that has implications for life.

Enceladus likely has ice pumping, but it’s expected to be weaker than on Europa because Enceladus’ gravity is much weaker. Image Credit: NASA/JPL/Space Science Institute

“We show that ice pumping can occur for a range of ocean salinity and ice thicknesses relevant to ocean worlds and that ice pumping is an important process linking ice shell dynamics, ocean circulation, and basal ice shell topography,” the authors write. “We show that the relationship between ice-ocean interactions and ice topography establishes a link between variability in ocean temperature and ice shell thickness that potentially makes constraining ocean temperatures possible in the absence of in situ ocean observations.”

That’s a big step. The more we can learn about these worlds without visiting them, the better. Missions to the Solar Systems icy moons are expensive, though one is already planned: NASA’s Europa Clipper. It’s scheduled for launch later this year and should arrive at Jupiter in 2030. A combination of methods will help the Clipper measure Europa’s ice thickness more accurately.

“The concepts described here will enable the thermal state of Europa’s upper ocean to be constrained from ice shell thickness,” the authors conclude.

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The Apollo Program delivered 12 American astronauts to the surface of the Moon. But that program ended in 1972, and since then, no human beings have visited. But Artemis will change that. And instead of just visiting the Moon, Artemis’ aim is to establish a longer-term presence on the Moon. That requires more complexity than Apollo did. Astronauts will need to transfer between vehicles.

All of that activity requires a reliable spacecraft docking system.

When Artemis astronauts blast off from Earth, they’ll be in the four-seat Orion spacecraft. Orion will take them to lunar orbit, where two will transfer into the Starship HLS, and two will remain in Orion. Starship HLS will deliver them to the lunar surface. In the future, the Lunar Gateway will be in orbit around the Moon, and astronauts will move from Orion to the Gateway to the Starship HLS.

These transfers are complicated and risky maneuvers. The docking system that will make this work is called SpaceX’s Starship HLS docking system. It’s based on SpaceX’s successful Dragon 2 docking system. The Dragon 2 system allows the Dragon 2 spacecraft to dock with the ISS so crew and equipment can be transferred. It’s been in use since 2020.

NASA and SpaceX are busy testing the new Starship HLS docking system. They recently completed ten days of testing at the Johnson Space Centre in Houston, Texas. They conducted more than 200 different docking scenarios involving different speeds and angles. The results from this full-scale testing will feed into ongoing computer models of the system, which will, in turn, feed into future testing and design.

This graphic shows the Artemis III Concept of Operations. Docking and crew transfers are a critical stage in the missions. Image Credit: NASA

The system has both an active and a passive mode. When two spacecraft dock, one is active, and the other is passive. The active one is called the chaser, and the other is the target.

During this round of tests, NASA and SpaceX demonstrated the soft capture procedure. In passive capture, the chaser extends its soft capture system (SCS) while the target spacecraft’s system remains retracted. The chaser does all the work, employing latches and other mechanisms to grab the target spacecraft and complete the docking.

HLS requirements state that there must be redundancy in crew egress/ingress. The soft capture procedure seems to address this if the docking system works while one docking system remains retracted.

This is just the latest round of tests. SpaceX has already reached a series of important milestones for the Starship HLS. Those milestones involved power generation, communications, guidance and navigation, propulsion, life support, and space environments protection.

While watching powerful rockets being tested and launched takes up a lot of attention, there’s far more to successful missions than just launch vehicles. According to NASA, “the Human Landing System program is at the center of Artemis, designed to yield groundbreaking science, develop and utilize lunar
surface resources and leverage what we learn at the Moon for future Mars missions.” Docking systems might not garner much attention, but they’re obviously a critical part of success.

Through that lens, any progress on Artemis is good news because, on other fronts, the news is not always good. Artemis was initially scheduled to launch in 2025. But it’ll be at least a year late, and NASA says that SpaceX will need to perform more launches before the Artemis mission is given the go-ahead.

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Well it certainly caught my attention when I saw the headlines  “China’s first Space Environment Simulator” sounds like something right out of an adventure holiday. Whilst you can’t buy tickets to ‘have a go’ it’s actually for China to test spacecraft before launching them into the harsh environments of space. It allows researchers to simulate nine environmental factors; vacuum, high and low temperature, charged particles, electromagnetic radiation, space dust, plasma, weak magnetic field, neutral gasses and microgravity – and it even looks futuristic too!

The Harbin Institute of Technology and the China Aerospace Science and Technology Corporation developed the simulator as part of China’s first large scale scientific facility. It’s official name is the Space Environment Simulation and Research Infrastructure facility, or SESRI for short and it will provide focus to explore the environments of space with focus on space craft and life forms and also on plasma (charged gas) interactions. 

The facility covers an area the size of 50 soccer fields, has four main laboratories and has the ability to tailor the environmental conditions based on research requirements. Each one covers a different aspect of space exploration for example the Lunar Dust Simulation chamber studies the impact of dust on spacecraft, astronauts and their spacesuits. Any space faring person or craft is subjected to extreme temperature fluctuations, to elevated levels of charged particles and electromagnetic radiation and to higher levels of space dust and all of these are adjustable with the simulator.

Spacecraft and suits are subjected to dust on the Moon and (one day) other worlds. Sample collection on the surface of the Moon by Apollo 16 astronaut Charles M. Duke Jr. is shown collecting samples with the Lunar Roving Vehicle in the left background. Image: NASA

Some experiments that previously required time in space will no longer have to be launched and can be completed on the ground in a far more controlled, safer and even cheaper environment. Deputy Commander in Chief of the project Li Liyi even mused that it was akin to bringing the space station to Earth. In addition to offering and simulating the environment to test space craft, it will also allow for agricultural breeding and life science experiments to explore humans reaction and interaction to long term colonies on other planets. 

The official opening came after 18 years of work from start to finish and hopes to establish China as one of the world’s main aerospace powers. It has already received interest from as many as 110 universities and institutes from over 30 countries. 

SESRI holds great importance to China in facilitating scientific and technological breakthroughs that can span across technologies, sciences and even industries. But China’s aspiration’s don’t stop there. They hope it will help to unravel some of the mysteries of the universe and reveal scientific laws that govern the cosmos we see today. 

Source : Nation opens first simulated environment for space research

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Only the other week I had to fix my leaky tap. That was a nightmare.  I cannot begin to imagine how you deal with a leaky spacecraft! In August 2020 Russia announced that their Zvezda module had an air leak. An attempt was make to fix it but in November 2021 another leak was found. Earlier this week, Russia announced the segment is continuing to leak but the crew are in no danger. 

It’s amazing to think that the International Space Station that has graced many a night sky, was launched back in 1998. A wonderful piece of international co-operation between US, Russia, Canada, Japan and the countries of the European Space Agency, it has been orbiting Earth ever since providing a ‘zero gravity’ laboratory for research into all manner of things. Orbiting at an altitude of about 400 km it comprises 16 pressurised modules that have supported research in the fields of biology, physics, engineering and astronomy. 

The Zvezda module (whose name means star) was the third module to be launched to the station and provides all of the life support systems which are supplemented by the US Orbital Segment and the living quarters. The main structure of the module was built in the mid-1980’s to be destined for the Mir Space Station. It consists of a cylindrical ‘work compartment’ for the crew to live and work and its this which is the main bulk of the module. There is a smaller spherical Transfer Compartment at the front end and a cylindrical Transfer Chamber to the rear. These two Transfer units provide the capability to connect the module with other modules of the station.  The Transfer Chamber is surrounded by the Assembly Compartment which is unpressurised and home to thrusters, antennae, thermometers and propellant tanks. 

A diagram showing the on-orbit configuration of the Zvezda Service Module of the International Space Station. Credit – NASA

Russian officials have stated that specialists are engaged in monitoring the leas in the Zvezda module and the crew regularly conduct work to locate and fix possible leaks.  They do stress however that there is no threat to the crew or station. 

If that wasn’t enough to worry any of the inhabitants (and I’m sure they must be a little concerned) the officials went on to report that the leaks in the module have increased but operations are not currently at threat. This is off the back of the leaks identified and fixed in 2020 and 2021. It’s not just air leaks either; there have been coolant leaks from the external backup radiator, coolant leaks from the Russian Soyuz spacecraft docked at ISS and even leaks from the Progress supply ship in February 2023.

Whilst some of the leaks have been attributed to damage from tiny micrometeoroid impacts, the station is getting old now and maintenance and repair tasks seem to be on the increase. 

Source : Russian space officials say air leak at International Space Station poses no danger to its crew

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Universe Today has surveyed the importance of studying impact craters, planetary surfaces, exoplanets, astrobiology, solar physics, and comets, and what these fantastic scientific fields can teach researchers and space fans regarding the search for life beyond Earth. Here, we will discuss how planetary atmospheres play a key role in better understanding our solar system and beyond, including why researchers study planetary atmospheres, the benefits and challenges, what planetary atmospheres can teach us about finding life beyond Earth, and how upcoming students can pursue studying planetary atmospheres. So, why is it so important to study planetary atmospheres?

Dr. Brian Toon, who is a Professor and Research Scientist in the Department of Atmospheric and Oceanic Sciences at the University of Colorado, Boulder, tells Universe Today, “There are many reasons to study planetary atmospheres. For example, we think the sun was much dimmer in the early history of the solar system, yet Earth and Mars each were as warm or warmer than now. How is this possible? Venus and Mars have carbon dioxide dominated atmospheres with more CO2 in the vertical column than Earth. Yet one is colder than Earth and the other warmer. Even though Venus is closer to the sun its clouds reflect so much light that it effectively has less sunlight than Earth, yet its surface is warm enough to melt lead. How is this possible? We need to understand other atmospheres to understand the past and future of Earth.”

Image of Mars with its thin atmosphere comprised primarily of carbon dioxide obtained by NASA’s Viking 1 orbiter in 1976. (Credit: NASA) Ultraviolet and filtered image of Venus with its thick and cloudy atmosphere obtained by the Japanese Aerospace Exploration Agency’s (JAXA) Akatsuki spacecraft on May 23, 2018. (Credit: JAXA/ISAS/DARTS/Kevin M. Gill)

Aside from Earth, Venus, and Mars, the other planetary bodies in our solar system that possess atmospheres include Jupiter, Saturn, Uranus, Neptune, dwarf planet Pluto, and Saturn’s largest moon, Titan, which is the only solar system moon with a dense atmosphere. The formation and evolution of these atmospheres are what scientists are attempting to better understand via computer models that are often combined with data obtained by ground- or space-based telescopes. Through this, scientists have learned, and continue to learn, a great deal about the atmospheres of these intriguing and mysterious worlds that inhabit our solar system. But even with all the instruments and technological advancements, what are some of the benefits and challenges of studying planetary atmospheres?

Image of Saturn’s largest moon, Titan, and its dense atmosphere comprised of nitrogen and methane obtained by NASA’s Cassini spacecraft on July 3, 2004. (Credit: NASA/JPL/Space Science Institute)

“The same climate models used for Earth are now used for other planets, such as Mars,” Dr. Toon tells Universe Today. “When the models fail on Earth it is tempting to force them to match Earth data rather than fixing the physics and chemistry in the models. Having the examples from other planets force us to look for errors in Earth models or in our understanding of how Earth climate models work.”

Planetary atmospheres within our own solar system range from sulfuric acid and carbon dioxide (Venus) to carbon dioxide (Mars) to hydrogen and helium (Jupiter, Saturn, Uranus, and Neptune) to nitrogen and methane (Titan and Pluto). Despite the sulfuric acid within Venus’ atmosphere, past studies have postulated the possibility of Venus’ higher altitudes potentially having the ingredients to support life as we know it. Therefore, these unique worlds could offer a glimpse of what scientists could find beyond our solar system, known as exoplanets. But what can studying planetary atmospheres within our own solar system teach us about exoplanet atmospheres?

Dr. Toon tells Universe Today, “We expect a wide range of exoplanetary atmospheres, some are so hot that they likely are raining metals. Even in the solar system there are planets raining condensed natural gas. So, the solar system planets are analogs for exoplanets, but there are definitely exoplanets very different from solar system planets.”

Since the distance to exoplanets ranges from a few light-years to hundreds of light-years, it takes extremely powerful instruments to study their atmospheres. One example is NASA’s James Webb Space Telescope (JWST), which has examined the atmospheres of several exoplanets, including WASP-39 b, which is located just under 700 light-years from Earth. With its powerful infrared instruments, JWST successfully identified water, carbon dioxide, and potassium on this Jupiter-sized world. As demonstrated on Earth, water is essential for life as we know it. Therefore, finding water on an exoplanet could indicate its likelihood for life, as well.

Atmospheric data of WASP-39 b obtained from NASA’s James Webb Space Telescope, which identified water, carbon dioxide, and potassium. (Credit: NASA, ESA, CSA, Joseph Olmsted (STScI))

However, out of the almost 5,600 confirmed exoplanets as of this writing, only 69 are deemed potentially habitable. This is primarily due to their orbit residing within their star’s habitable zone (HZ), meaning they orbit at the correct distance from their star for liquid water to potentially exist on its surface, assuming the exoplanet is terrestrial (rocky) like Earth. But finding water within an exoplanet’s atmosphere could also pose the prospect for finding life, as well. Therefore, what can studying planetary atmospheres teach us about finding life beyond Earth?

“The Earth’s atmosphere is out of chemical balance due to emissions of various gases by life,” Dr. Toon tells Universe Today. “For example, the oxygen in Earth’s atmosphere is not compatible with the methane in the atmosphere. The methane is largely a waste product of life. So, trying to detect life elsewhere is most likely going to start with looking at the chemistry of exoplanet atmospheres for signs of chemical imbalance.”

The scientific discipline responsible for studying planetary atmospheres is known as atmospheric science and encompasses several subdisciplines, including computer science, astronomy, physics, and meteorology, just to name a few. It is through constant collaboration and innovation of these subdisciplines that allows scientists to study planetary atmospheres both within and beyond our solar system. As noted, the planetary atmospheres within our solar system provide a wide range of diversity and scientists have observed the same diversity on exoplanets, as well. So, what is the most exciting planetary atmosphere(s) that Dr. Toon has studied during his career?

“I have studied every atmosphere in the solar system, and some exoplanets,” Dr. Toon tells Universe Today. “The most interesting is Mars, because there is a lot of data for Mars, and Mars once had a climate more like Earth’s than the barren desert it is now. Titan, a moon of Saturn is also interesting because it has methane rain, and lakes and seas of hydrocarbons. It also is shrouded in a haze composed of complex organic material.” Additionally, what advice can Dr. Toon offer upcoming students who wish to pursue studying planetary atmospheres?

“I suggest students first learn about the Earth’s atmosphere,” Dr. Toon tells Universe Today. “It is surprising how many astronomers looking at planetary atmospheres don’t know about parallels with Earth.”

How will planetary atmospheres help us better understand our place in the universe in the coming years and decades? Only time will tell, and this is why we science!

As always, keep doing science & keep looking up!

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If future explorers manage to set up communities on Mars, how will they pay their way? What’s likely to be the Red Planet’s primary export? Will it be Martian deuterium, sent back to Earth for fusion fuel? Raw materials harvested by Mars-based asteroid miners, as depicted in the “For All Mankind” TV series? Or will future Martians be totally dependent on earthly subsidies?

In a new book titled “The New World on Mars,” Robert Zubrin — the president of the Mars Society and a tireless advocate for space settlement — says Mars’ most valuable product will be inventions.

“We’re talking about creating a new and potentially extremely inventive branch of human civilization, which will benefit humanity as a whole enormously,” he says in the latest episode of the Fiction Science podcast. “But moreover, we’ll play from that strength to make money.”

Zubrin isn’t waiting until humans step foot on Mars to get started.

“We are in the process of drawing up business plans for two major initiatives — one in the artificial intelligence area and the other in the synthetic food production area,” he says. “And the idea is, fairly soon we’re going to be presenting these business plans to investors, with the idea of starting companies devoted to these two different technological ideas that we have put together.”

Zubrin says it’s too early to reveal exactly what these companies would do, but he claims the ventures have the potential to become extremely profitable. The AI concept could be “a billion-dollar idea,” he says.

“They’re both addressing critical questions for Mars that have tremendous terrestrial spin-off potential,” Zubrin says.

Income from the ventures would be split between investors and the Mars Society, which would use the funds to support a Mars Technology Institute. “We just did a fundraising drive and raised $150,000 to get this thing started,” Zubrin says.

Robert Zubrin is the founder and president of the Mars Society. (Credit: Mars Society CC BY-SA 3.0)

Once things get rolling, Zubrin envisions setting up a headquarters for the institute — perhaps in the Pacific Northwest or in Colorado (where the Mars Society is currently based).

The concept of using earthly ventures to support off-Earth adventures is by no means new. Back in 2015, when SpaceX founder Elon Musk was recruiting engineers for the Starlink satellite internet network, he said the profits from Starlink would go toward funding a city on Mars.

“Looking in the long term, and saying what’s needed to create a city on Mars — well, one thing’s for sure: a lot of money,” Musk told an audience of about 400 techies (including prospective employees) in Seattle. “So we need things that will generate a lot of money.”

Zubrin says the challenge of establishing settlements on Mars will promote invention in the same way that the challenges facing pioneers in the United States led to innovations ranging from steamboats to light bulbs to iPhones.

“Mars is even going to be much more technologically selective in terms of who goes there, and also a much more challenging environment,” he says. “It’s going to be America to the third power in terms of what it will be able to invent.”

He argues that settlers will be forced to innovate when it comes to developing nuclear fission and fusion plants for energy, finding ways to conserve and recycle resources for sustaining Martian communities, and maximizing food production amid the planet’s harsh conditions. All those innovations can then be exported back to Earth.

Zubrin has laid out the case for Mars settlement in a series of books that goes back to, well, “The Case for Mars” in 1996. He also wrote a fictional account of a crewed mission to Mars, titled “First Landing.” And he has appeared in more than a dozen TV shows about Mars and space exploration, including “Mars,” a National Geographic series that blends science fiction and science fact.

“The New World on Mars” deals with thematic territory that spreads out much more broadly than what was covered in “The Case for Mars.” And Zubrin says SpaceX’s rise is the reason why.

For years, Musk and his team have been focusing on development of a reusable super-heavy-lift launch system known as Starship. The next test flight could take place within weeks — and it’s likely to be only a matter of time before Starship offers a reliable way to get to Earth orbit and beyond.  Musk envisions building a fleet of the rockets to send thousands of settlers to Mars, in line with his long-term ambition to make humanity a multiplanet species.

“The New World on Mars: What We Can Create on the Red Planet” by Robert Zubrin. (Diversion Books)

Zubrin assumes that Starship or something like it will be a success — which means there’s less need to dwell on the nuts and bolts of interplanetary transport in “The New World on Mars.”

“This book essentially says, ‘Look, it’s soon going to be possible for humans to go to Mars,’” he says. “So the key question is not how do we do that, but what do we do when we get there?”

Zubrin goes into great detail about how Mars’ harsh realities could affect every aspect of daily life, from energy production and terraforming to marriage and parenthood. For example, he suggests that Martians might clean their clothes simply by airing them out in the Red Planet’s low-pressure, bacteria-killing environment.

Zubrin went so far as to test the technique by stuffing dirty clothes into a laboratory vacuum chamber. “The only downside is that stains are not removed, so they don’t look clean. One remedy for this would be to use camo coloration for clothes, as it does not show stains,” he writes. “I predict this will be the style.”

“The New World on Mars” is more optimistic about Red Planet settlement than “A City on Mars,” a book by Kelly and Zach Weinersmith that was featured on Fiction Science last November. That book argues that the drive to create space settlements is premature — and that a host of uncertainties need to be cleared up first. For example, the Weinersmiths say that much more research should be done on the potential effects of Mars’ reduced gravity on human reproduction and development. They also raise concerns about the potential international conflicts over property rights in space.

As you’d expect, Zubrin strongly disagrees with such views — in his book, on the podcast, and in a book review published by Quillette. “They say there’s no point going into space. There’s nothing to be gained from it, and therefore, there should be laws to stop it, which makes no sense whatsoever,” he says.

In Zubrin’s view, the 1967 Outer Space Treaty’s prohibition on claims of national sovereignty won’t tie the hands of Mars settlers. Instead, it would make it easier for them to stake their own claims. “If a Martian colony is set up, and declares property rights within its vicinity, [governments on Earth] have no jurisdiction to contradict it,” Zubrin says. “They have explicitly signed away their rights to interfere with Mars settlement.”

And what about the health effects of living on Mars? “OK, so yeah, we don’t know about the long-term effects of one-third gravity on people, but we’ll find that out,” Zubrin says. “When we send our first exploration missions to Mars, I believe it’ll be OK.”

The way Zubrin sees it, the main attraction for Mars settlers won’t be deuterium, or asteroid riches, or shiny red obsidian. It’ll be something money can’t buy: the freedom to create.

“I believe that there’s nothing more powerful than the creative power of life,” he says. “The grass finds a way to break through the pavement. Life finds a way. … And freedom is going to find a way.”

Check out the original version of this posting on Cosmic Log for Red Planet reading recommendations from Robert Zubrin.

My co-host for the Fiction Science podcast is Dominica Phetteplace, an award-winning writer who is a graduate of the Clarion West Writers Workshop and lives in San Francisco. To learn more about Phetteplace, visit her website, DominicaPhetteplace.com, and read “The Ghosts of Mars,” her novella in Asimov’s Science Fiction magazine.

Stay tuned for future episodes of the Fiction Science podcast via Apple, Google, Overcast, Spotify, Player.fm and Pocket Casts. If you like Fiction Science, please rate the podcast and subscribe to get alerts for future episodes.

The post How Startups on Earth Could Blaze a Trail for Cities on Mars appeared first on Universe Today.

Astronomers have detected a large amount of water vapour in the protoplanetary disk around a young star. There’s at least three times as much water among the dust as there is in all of Earth’s oceans combined. And it’s not spread throughout the disk; it’s concentrated in the inner disk region.

No water means no life, so finding this much water in the part of a protoplanetary disk where rocky planets form is an intriguing discovery. And this isn’t just any disk. It’s a cold, stable disk, the type most likely to form planets.

The findings are presented in a new paper published in Nature Astronomy. It’s titled “Resolved ALMA observations of water in the inner astronomical units of the HL Tau disk.” The lead author is Stefano Facchini, an astronomer at the Dipartimento di Fisica, Università degli Studi di Milano, Milano, Italy.

“I had never imagined that we could capture an image of oceans of water vapour in the same region where a planet is likely forming,” said Facchini.

The star, HL Tau (HL Tauri), is a young star about 450 light-years away. It’s likely less than 100,000 years old, making it a prime observing target in the quest to understand planet formation. When it comes to seeing inside the gas and dust surrounding young stars like this, ALMA is our best tool. One of ALMA’s first high-resolution images is of HL Tau and its disk. The image shows rings in the disk that indicate where young planets are probably forming.

This is the sharpest image ever taken by ALMA — sharper than is routinely achieved in visible light with the NASA/ESA Hubble Space Telescope. It shows the protoplanetary disc surrounding the young star HL Tauri. These new ALMA observations reveal substructures within the disc that have never been seen before and even show the possible positions of planets forming in the dark patches within the system. Image Credit: ALMA

HL Tau has always intrigued scientists, and now that they’ve detected such a large amount of water vapour in its planet-forming disk, the young star is an even more compelling target for observations.

“These observations pave the way to the characterization of the water content of the inner regions of protoplanetary disks,” the researchers write in their paper. “The tremendous angular resolution and sensitivity of the ALMA telescope, even in spectral ranges of low atmospheric transmission, are providing spatially and spectrally resolved images of the vapour of the main water isotopologue in a planet-forming disk.”

Not only did ALMA detect the water, but it also determined where it is in the disk and how much of it there is. “Our analysis implies a stringent lower limit of 3.7 Earth oceans of water vapour available within the inner 17 astronomical units of the system,” the researchers write in their paper.

When planets take shape in a protoplanetary disk like the one around HL Tauri, they clear out lanes in the dust. Nothing else is likely to create the tell-tale gaps that signal the presence of young, still-forming planets. We have the powerful ALMA to thank for this understanding.

“It is truly remarkable that we can not only detect but also capture detailed images and spatially resolve water vapour at a distance of 450 light-years from us,” said study co-author Leonardo Testi, an astronomer at the University of Bologna, Italy. The spatial resolution Testi is referring to is thanks to ALMA. The radio interferometer allowed astronomers to see how the water vapour is distributed throughout the disk. “Taking part in such an important discovery in the iconic HL Tauri disc was beyond what I had ever expected for my first research experience in astronomy,” added Mathieu Vander Donckt from the University of Lie?ge, Belgium, a master’s student when he participated in the research.

ALMA is a radio interferometer, meaning it observes wavelengths from 0.3 mm to 3.6 mm, which correspond to the range from 84 GHz to 950 GHz. In this study, the researchers observed different “flavours” of water molecules at different temperatures. “We observed HL Tau in two different ALMA bands (band 5, originally developed with the goal of studying water in the local Universe, and band 7) to target three transitions of water,” the researchers explain.

This figure from the research illustrates some of the findings. The blue line is water detected by ALMA at 321 GHz, a high-excitation state for water vapour. The yellow line is water detected at 183 MHz, an important diagnostic line used in remote sensing of water vapour. Both lines indicate more water vapour in the inner regions of the disk. Image Credit: Facchini et al. 2024.

The observations didn’t just find water in the inner region where rocky planets form. It found water in one of the gaps that indicate a planet is sweeping up disk material and adding it to its mass. “Our recent images reveal a substantial quantity of water vapour at a range of distances from the star that includes a gap where a planet could potentially be forming at the present time,” said Facchini. The natural conclusion is that the water is becoming part of the planet.

These results are all thanks to ALMA’s power. It’s the only facility we have that can detect water in a disk like this. “To date, ALMA is the only facility able to spatially resolve water in a cool planet-forming disc,” said study co-author Wouter Vlemmings, a professor at the Chalmers University of Technology in Sweden.

ALMA’s different observational frequencies capture water as it transitions, and part of this research looks at water as it’s liberated from dust particles. The relationship between water and dust in a planet-forming disk is important. Where it’s cold enough for water to freeze onto dust particles, the particles stick together more readily, aiding the planet formation process.

“It is truly exciting to directly witness, in a picture, water molecules being released from icy dust particles,” said Elizabeth Humphreys, an astronomer at ESO who also participated in the study.

Some of what astronomers see in the disk around HL Tauri is like a window into the past. Our planet formed in a similar way, and the same processes and mechanisms must be similar from disk to disk.

“Our results show how the presence of water may influence the development of a planetary system, just like it did some 4.5 billion years ago in our own Solar System,” Facchini said.

ALMA really flexed its muscles in this work, and the facility has played a primary role in our study of protoplanetary disks around young stars. But upcoming telescopes will surpass ALMA and give us even deeper, more detailed looks inside the dusty, obscured disks. The Extremely Large Telescope is due to see first light in 2028. Its powerful METIS (Mid-infrared ELT Imager and Spectrograph) will give us unprecedented insight into the process of planet formation.

The post This Planet-Forming Disk has More Water Than Earth’s Oceans appeared first on Universe Today.

On October 19th, 2017, astronomers with the Pann-STARRS survey observed an Interstellar Object (ISO) passing through our system – 1I/2017 U1 ‘Oumuamua. This was the first time an ISO was detected, confirming that such objects pass through the Solar System regularly, as astronomers predicted decades prior. Just two years later, a second object was detected, the interstellar comet 2I/Borisov. Given ‘Oumuamua’s unusual nature (still a source of controversy) and the information ISOs could reveal about distant star systems, astronomers are keen to get a closer look at future visitors.

For instance, multiple proposals have been made for interceptor spacecraft that could catch up with future ISOs, study them, and even conduct a sample return (like the ESA’s Comet Interceptor). In a new paper by a team from the Southwest Research Institute (SwRI), Alan Stern and his colleagues studied possible concepts and recommended a purpose-built robotic ISO flyby mission called the Interstellar Object Explorer (IOE). They also demonstrate how this mission could be performed on a modest budget with current spaceflight technology.

The study was conducted by Alan Stern, the Principal Investigator for NASA’s New Horizons missions, and his colleagues at the Southwest Research Institute (SwRI) in Boulder, Colorado. This included Principal Scientist Silvia Protopapa, manager Matthew Freeman, researcher/director Joel Parker, and systems engineer Mark Tapley. They were joined by Cornell Research Associate Darryl Z. Seligman and Caden Andersson, a researcher with Colorado-based company Custom Microwave Inc. (CMI). Their paper appeared on February 5th, 2024, in the journal Planetary and Space Science.

The Vera C. Rubin Observatory is under construction at Cerro Pachon in Chile. The observatory should be able to spot interstellar objects like ‘Oumuamua. Credit: Wil O’Mullaine/LSST Interstellar Objects (ISOs) Abound!

Since ‘Oumuamua first buzzed our system, scientists have assigned a high value to ISOs, which represent material ejected from other solar systems. By obtaining samples and studying them up close, we could learn much about the formation of other stars and planets without actually sending missions there. We could also learn a lot about the interstellar medium (ISM) and how organic material, and maybe even the building blocks for life, are distributed throughout the galaxy (aka. Panspermia Theory). As they state in their paper:

“ISOs represent the leftovers from the formation of planetary systems around other stars. As such, their study offers critical new insights into the chemical and physical characteristics of the disks from which they originated. Additionally, a comprehensive analysis of their composition, geology, and activity will shed light on the processes behind the formation and evolution of planetesimals in other solar systems.

“Close encounters with small bodies in our solar system have vastly enhanced our understanding of these objects, contextualized our ground-based observations, and advanced our knowledge of planetesimal formation models. Similarly, a close flyby of an ISO promises to be equally transformative. It stands as the logical next step in exploring the early history of both our Solar System and exoplanetary systems.”

Moreover, population studies of ISOs have indicated that about seven pass through our Solar System every year. Meanwhile, other research has shown that some are periodically captured and are still here. With next-generation instruments becoming operational, scientists anticipate that there will be a significant increase in the rate of ISO discoveries in the late 2020s and the 2030s. This includes the Vera C. Rubin Observatory currently under construction in Chile, which is expected to gather its first light in January 2025.

Researchers anticipate the observatory will gather data on more than 5 million Asteroid Belt objects, 300,000 Jupiter Trojans, 100,000 near-Earth Objects (NEOs), and more than 40,000 Kuiper Belt objects. They also estimate that it will detect about 15 interstellar objects in its first ten-year run, known as the Legacy Survey of Space and Time (LSST) – though other estimates say up to 70 ISOs a year. For their study, Stern and his colleagues assume that any ISOs within a distance of about twice the distance between Earth and the Sun (2 AU) would be bright enough to be detectable by the LSST.

‘Oumuamua (l) and 2I/Borisov (r) are the only two ISOs we know of for certain. Image Credit: (left) ESO/M. Kornmesser; (right) NASA, ESA, and D. Jewitt (UCLA) Objectives and Instruments

As Stern and his colleagues explain in their paper, their proposed IOE would have two main science objectives. These include determining the “composition of the ISO to provide insights into its origin and evolution.” As noted, these studies would provide invaluable information on the initial conditions of the ISO’s host solar system. In this respect, the IOE would provide information similar to what the New Horizons mission revealed about the Kuiper Belt Object (KBO) Arrokoth or how the ESA’s Rosetta mission detected the building blocks of life in the comet 67P/Churyumov–Gerasimenko.

Second, the IOE would determine or constrain the “nature, composition, and sources of the ISO coma activity and determine the processes responsible for [the] observed activity.” Typically, coma activity results from ice sublimating as objects approach a star, which releases dust grains and refractory organic molecules from the nucleus. As previous observations have shown, the activity of comets depends on solar heating and the comet’s own physical characteristics. As Stern and colleagues expressed in their paper:

“By characterizing the composition and spatial distribution of an ISO’s coma, IOE can directly determine the primary components of its target ISO, identify the mechanisms behind coma activity, and deepen our insights into the composition and processes extant in its protoplanetary formation disk, where planetesimals like it were forming… Furthermore, comparing the physical properties (i.e., the chemical composition, size distribution, type of mixing) of ices and refractories in the coma with those on the surface can provide insights into potential processes that may have modified the surfaces.”

Based on these science objectives, Stern and his colleagues listed what instruments the IOE would need. These include:

• A panchromatic visible-wavelength imager with arcsecond-class angular resolution and high dynamic range
• A visible-wavelength imager with three filters (min) and an infrared imaging spectrometer that spans the 1–2.5 um wavelength range (possibly up to 4 um) with a resolving power of at least 100
• An ultraviolet (UV) spectrometer spanning the wavelength range of 700–1970 angstrom (Å) with a spectral resolution of equal or greater than 20 Å
• A panchromatic visible-wavelength imager and UV and infrared imaging spectrometers

Artist’s impression of a swarm of laser sail spacecraft arriving at ‘Oumuamua, the interstellar asteroid. Credit: Maciej Rebisz Mission Profile

Next up is the design of the spacecraft itself, which is dictated by the ephemeral nature of ISOs. As ‘Oumuamua and Borisov demonstrated, the velocity of ISOs means that they are likely to remain undetected until they are close to the inner edge of the Main Asteroid Belt. In addition, their hyperbolic trajectories mean that they are likely to zip around our Sun and become unreachable shortly after they are detected. Last, there’s the positioning of the intercept mission itself, which directly affects the spacecraft’s ability to deploy and reach the target ISO.

For their study, Stern and his team selected a “storage orbit” location at the Earth-Moon L1 Lagrange Point, located between the Earth and Moon. This location has several advantages, most notably how a spacecraft positioned will need to generate very little thrust to achieve escape velocity – meaning that most of its available acceleration (delta-v) will be put towards its intercept trajectory. This storage orbit also means less propellant and less time is needed to get underway, and allows for a quick gravitational assist from a near-Earth flyby.

For their study, Stern and his team set a detectability limit of 2 AU and simulated ISOs with a mean velocity of 32.14 km/s (~20 mps) and a closest solar approach of 10 AU or less. Other constraints that were considered included the positions of the Earth and ISO at the time of its detection, the ISO’s orbit parameters, the maximum distance that a mission could intercept an ISO (aka. the “heliocentric radius of intercept”), and the relative velocity between the spacecraft and ISO. To effectively analyze this data, the team generated an algorithm to optimize the intercept trajectory and establish a small subset of ISOs that could feasibly be intercepted.

They simulated all of these calculations over a period of 10 years and (using previous missions as precedents) derived several key parameters. As they established, the mission would need to be capable of an acceleration (delta-v) of 3.0 km/s, establish a minimum flyby altitude of 400 km (~250 mi), intercept the ISO within 3 AUs of the Sun, and achieve a flyby velocity of 100 km/s (62 mps). With this “detectability sphere” established, they found that the chances for a successful intercept increased considerably at higher velocities – 3 to 3.9 km/s (1.86 to 2.4 mps) – and at distances closer to 3 AU.

The study of ISOs is a burgeoning field of astronomical research encompassing next-generation observatories (like Vera Rubin) and proposed intercept missions. In addition to the IOE, similar concepts have been proposed since the detection of ‘Oumuamua and 2I/Borisov – including Project Lyra, a proposal made by the Institute for Interstellar Studies (i4is). While such a mission may be years from realization, detailed studies such as this will help inform the next phase of development – the designing and testing of mission concepts themselves.

Stern and his colleagues acknowledge that more research is needed before this can happen but emphasize that their work is an important first step. “More detailed work will be needed next to better prepare the mission concept to be proposed to a future NASA mission opportunity,” they write, “but this report provides the mission’s basic objectives, key requirements, and attributes as a starting point.”

Further Reading: Planetary and Space Science

The post When an Object Like ‘Oumuamua Comes Around Again, We Could be Ready With an Interstellar Object Explorer (IOE) appeared first on Universe Today.