Universe Today Feed

As the search for extraterrestrial life continues, scientists have identified the hidden oceans beneath icy moons as target locations for discovery. However, new research from the University of Reading suggests these alien seas may be better at masking their secrets than previously believed. Thick ice layers and complex chemical processes could make detecting signs of life from spacecraft far more challenging. The discovery presents significant obstacles for future missions to moons like Europa and Enceladus, where subsurface oceans might host the clues needed to finally confirm life beyond Earth.

Europa, one of Jupiter’s largest moons, has a subsurface ocean beneath an icy crust. Research to date suggests that this hidden ocean, kept liquid by tidal heating from the gravity of Jupiter, could contain the necessary ingredients for life, including water, energy, and essential chemicals. Surface features such as cracks and ridges suggest that water from the ocean occasionally seeps through the ice, possibly carrying organic material to the surface. NASA’s upcoming Europa Clipper mission aims to investigate the moon’s habitability by analyzing its surface and subsurface environment. If life exists beyond Earth, Europa’s ocean may be one of the best places to find it.

Europa captured by Juno

Another location where life could be found in our Solar System is Saturn’s moon Enceladus. It’s perhaps one of the most fascinating of all Saturn’s moons with, just like Europa, it’s thought to have a global ocean beneath an icy crust. Water vapour escapes as jets through cracks in the crust near the south pole. A new study that has been published in Communications Earth & Environment shows how the ocean of Enceladus is separated into distinct layers. These layers impeded the movement of material from the ocean floor, where life is thought to exist, to the surface. 

True-color image of Enceladus’ plumes emanating from its south pole. (Credit: NASA / JPL-Caltech / SSI / Kevin M. Gill)

Spacecraft visiting worlds like Enceladus hunt for traces of chemicals like microbes and organic compounds are searched for among the water spraying out of the surface. However these ocean layers may well break down as they ascend through the ocean. By the time they reach the surface the biological signatures that would have been familiar are unrecognisable. It’s just possible that this process could hide signs of life that exist deep on the floor of the alien oceans. 

Flynn Ames, the lead author of the paper from the University of Reading explains that the oceans behave like oil and water in a jar with the distinct layers resisting vertical mixing. 

“These natural barriers could trap particles and chemical traces of life in the depths below for hundreds to hundreds of thousands of years. Previously, it was thought that these things could make their way efficiently to the ocean top within several months.”

A black smoker hydrothermal vent discovered in the Atlantic Ocean in 1979. It’s fueled from deep beneath the surface by magma that superheats the water. The plume carries minerals and other materials out to the sea. Courtesy USGS.

It seems then that simply sampling the escaping surface waters may not be sufficient to detect signs of life. Computer models have been established that are similar to those used to study our own oceans. The results revealing implications for our search for aliens in our Solar System. We may yet have to do more than simply analyse water spraying through surface cracks and fissures. Missions have been discussed that could launch tiny submarines to explore the oceans beneath the ice. It may be the only way we can find out once and for all if life does exist in the deep waters beneath the icy crusts.

Source : Alien ocean could hide signs of life from spacecraft

The post Alien Oceans May Conceal Signs of Life from Spacecraft appeared first on Universe Today.

As part of their ongoing mission to push the boundaries of space exploration, NASA’s cutting-edge robotic hand is bringing us one step closer to a future where machines can grab objects just like humans. The machine which has been designed for dexterity and precision, isn’t just about gripping objects—it’s about revolutionising how astronauts and robots work together in space. With applications ranging from spacecraft maintenance to cleaning up space junk, this high-tech hand is paving the way for a new era of spacecraft operations.

Satellites have revolutionised modern life, bringing us global communication and navigation to weather forecasting and scientific discovery. However, as space becomes increasingly crowded, a growing threat grows above us—space debris. Thousands of decommissioned or unused satellites, spent rocket stages, and fragments from past collisions now orbit Earth at high speeds, posing serious risks to spacecraft and future missions. As space agencies and private companies launch more satellites than ever before, finding solutions to manage and mitigate space debris has become a critical challenge for the future of space exploration.

An artist’s conception of ERS-2 in orbit. ESA

Space debris is a particular problem that NASA’s new Astrobee system is ideally placed to address. With over 36,000 pieces of debris larger than 10cm and over 100 million smaller than 1cm, all orbiting Earth at speeds in excess of up to 28,000 km per hour it’s a problem we must start to deal with. 

Orange balls of light fly across the sky as debris from a SpaceX rocket launched in Texas is spotted over Turks and Caicos Islands on Jan. 16, in this screen grab obtained from social media video. Credit: Marcus Haworth/Reuters

Astrobee is a free-flying robotic system that has been initially designed to help astronauts on board the International Space Station (ISS.) The system is composed of three cube shaped robots that have been named Bumble, Honey and Queen! The system could navigate around the ISS without human intervention using their sensors to see. The system also comprises of an arm that allows it to grab onto handrails on board to stabilise itself and conserve energy. 

The International Space Station (ISS) in orbit. Credit: NASA

The system, that was designed at the NASA’s Ames Research Centre has been on board the ISS since 2019 but it could go much further. It’s certainly been of great help around the ISS but deployed into orbit with a suitable propulsion system and power source, the sensor guided robotic arm could grab onto and manipulate pieces of debris. It could ultimately be used to collect debris like a space based road cleaner. 

Astrobee isn’t the only approach being taken to cleaning up the debris in space. The European Space Agency have also been experimenting with robotic arms and nets in their  ClearSpace-1 programme which aims to capture debris using robotic arms or nets and deorbit it safely. There is also talk of using harpoons to capture debris too but, and whilst I love the idea of harpoons around to grab debris it feels like it could be a dangerous option. 

Lasers are another option that has been considered as has ground based tethers, the use of solar sails and other de-orbit technology. Whichever technique works, it’s great to see space agencies around the World taking space debris and its clean up seriously. Hopefully if Astrobee can prove itself it too can join the ranks of growing janitors to our Solar System. 

Source : Robot Gets a Grip

The post NASA Gets a Firm Grip on the Future of Space Exploration appeared first on Universe Today.

At the end of 2024, astronomers detected an asteroid in the night sky. It was given the designation Y, since it was discovered in the last half of December, and R4 since it was the 117th rock to be found in the last couple of weeks of December, and since it was discovered in 2024, it was assigned the name 2024 YR4. Naturally, once a rock is found, astronomers start keeping track of it, measuring its position to get a handle on its orbit. In this case, the estimated orbit put it at a 1% chance of striking Earth. As more measurements were taken, those odds have more than doubled. As of this writing, it now has a 2.3% chance of striking Earth on December 22, 2032. While you might think this resembles the plot of Don’t Look Up, none of this is too unusual.

You can see this in the image above, which indicates potential trajectory points. The 2.3% odds aren’t simply the chances of a die roll. What it means is that when astronomers run 1,000 orbital simulations based on the data we have, 23 of them impact Earth. The most probable trajectory currently estimates that it will have a close approach of 240,000 km from Earth, which is within the orbit of the Moon but not dangerously close. So while the odds have doubled, astronomers aren’t too worried. When 2024 YR4 had a risk of less than 1%, NASA’s Planetary Defense Coordination Office (PDCO) ranked it a 3 on the Torino scale, meaning we should keep an eye on it. At a 2.3% risk, it is still a 3.

When it comes to tracking asteroids like this, the one thing we are certain of is that early estimates are uncertain. Unlike the orbits of planets, the orbits of asteroids can be remarkably fuzzy. Gravitational tugs from nearby objects can shift them around. In the case of 024 YR4, one big source of uncertainty is Earth itself. In 2028, it will pass within 8 million kilometers of Earth. This is actually when astronomers will be able to make much more precise measurements of its orbit. We will then see whether we need to start making plans. Even if astronomers find out the odds of impact are almost 100%, we still wouldn’t need to panic, for a few reasons.

Comparison of the dimensions of 2024 YR4 and other bodies. Credit: Wikipedia user Sinucep

The first is that we know it’s there. The real risk of asteroids isn’t from the ones slowly approaching Earth from the outer solar system. The bigger risks are ones such as Chelyabinsk which came from the direction of the Sun and caught us by surprise. We still have years to deal with 2024 YR4, and its orbit is such that we would have a good chance of deflecting it. And even if the absolute worst-case scenario were to occur, 2024 YR4 isn’t large enough to cause an extinction event. The absolute nightmare scenario is that it would strike Earth in a heavily populated area. We’d have to evacuate people from the risk zone, but we would have a few years to do that. An impact would be bad, but we could minimize the risk significantly.

Even with all that said, it’s important to keep in mind that early trajectory calculations can vary significantly. The odds may rise significantly again before dropping, but the most likely outcome is that the odds will eventually drop to zero.

If you want to keep tabs on 2024 YR4, check out NASA’s Planetary Defense Page.

The post Yes, the Odds of an Asteroid Striking Earth Have Doubled. No, You Don’t Need to Worry appeared first on Universe Today.

On October 14th, 2024, NASA’s Europa Clipper mission launched atop a Falcon Heavy rocket from Launch Complex 39A at the Kennedy Space Center in Florida. It will spend the next few years traveling 2.9 billion km (1.8 billion mi) to reach Jupiter’s moon Europa, arriving in April 2030. Once it arrives in the system, the probe will establish orbit and conduct 49 close flybys of this “Ocean World” and search for chemical elements that could indicate the presence of life (biosignatures) in the moon’s interior. By July 2031, it will be joined by the ESA’s Jupiter Icy Moon Explorer (JUICE), which will conduct a similar search around Callisto and Ganymede.

As is customary, the mission team has been checking and calibrating the Clipper’s instruments since launch to ensure everything is in working order. The latest test involved the probe’s stellar reference units (or star trackers), which captured and transmitted the Europa Clipper’s first images of space. These two imaging cameras look for stars, which mission controllers use to help orient the spacecraft. This is critical when pointing the probe’s telecommunications antennas toward Earth so it can send and receive critical mission data.

The picture (shown below) is composed of three shots that show stars 150 to 300 light-years away. The starfield includes the four brightest stars of the constellation Corvus (Gienah, Algorab, Kraz, and Alchiba), the Latin word for crow—a bird in Greek mythology associated with Apollo. The starfield represents about 0.1% of the sky around the spacecraft, but this is enough for other spacecraft to determine its orientation. A 3D model of NASA’s Europa Clipper can be viewed in the agency’s interactive Eyes on the Solar System.

Contrary to what you might expect, orientation is a separate process from navigation and is critical to telecommunications and science operations. Whereas navigation is all about making sure the mission is headed in the right direction (by first determining where it is in space), orientation involves using star trackers to determine where the science instruments are pointed. This includes the Europa Imaging System (EIS), which will help scientists map the moon’s surface and its many mysterious features – the fractures, ridges, and valleys caused by resurfacing events.

The checkout phase has been happening ever since Europa Clipper launched in October, and these photos show that the latest instrument check was successful. Joanie Noonan of NASA’s Jet Propulsion Laboratory leads the mission’s guidance, navigation, and control operations. “The star trackers are engineering hardware and are always taking images, which are processed on board,” she said in a NASA press release. “We usually don’t downlink photos from the trackers, but we did in this case because it’s a really good way to make sure the hardware — including the cameras and their lenses — made it safely through launch.”

When the Europa Clipper reaches its destination, it will conduct 49 flybys of the moon and gather information using its nine science instruments. In addition to the EIS, the probe will rely on the Europa Thermal Emission Imaging System (E-THEMIS) to detect warmer regions that could be liquid water near the surface or plume activity. It will also carry two spectrometers – which measure light in the ultraviolet (UV) and infrared (IR) wavelengths – to determine the composition of Europa’s surface and atmospheric gases and measure the distribution of ices, salts, organics, and the warmest hotspots on Europa.

Other instruments include magnetometers that will measure Europa’s induced magnetic field, confirm the existence of its internal ocean, and determine its depth. There are also gravity and radar instruments that will measure the moon’s gravitational field and probe beneath the icy surface, a dust spectrometer and neutral gas mass spectrometer to identify the materials Europa ejects or vents into space, and a spectrometer to study the chemistry of the moon’s atmosphere and plumes and its subsurface ocean.

Could shallow lakes be locked away in Europa’s crust? Europa Clipper will find out. Credit: NASA

This advanced suite of instruments will help the Europa Clipper mission accomplish its three main science objectives: to determine the thickness of the moon’s icy shell, to investigate its composition, and to characterize its geology. In so doing, it will confirm (or deny) that Europa and its internal ocean have the necessary ingredients and conditions to support life. The mission’s detailed exploration will inform scientists about the conditions of other “Ocean Worlds” in the Solar System (and beyond) and their potential for habitability.

If the mission is successful and the Europa Clipper potential biosignatures, NASA may follow up with the proposed Europa Lander. This mission, if realized, will set down on Europa’s icy surface and study its composition and plume activity directly, the results of which could definitively prove the existence of extraterrestrial life. The Europa Clipper is currently 85 million km (53 million mi) from Earth and is traveling at a speed of 27 km per second (17 mps). The craft is rapidly approaching Mars, and on March 1st, engineers will steer the probe to take advantage of a gravity assist with the Red Planet.

Further Reading: NASA

The post Europa Clipper Tests its Star Tracker Navigation System appeared first on Universe Today.

Our Moon continues to surprise us with amazing features. Scientists recently shared new information about two canyons that branch out from a major lunar impact. The site is the Schrödinger basin near the Moon’s South Pole. It formed when an asteroid or possibly even a leftover planetesimal slammed into the surface. It took only minutes to dig out that huge crater and split the landscape to make two huge rifts that extend from the site.

According to David Kring of the Lunar and Planetary Institute in Houston, TX, the impact is of very ancient origin. “Nearly four billion years ago,” he said, “an asteroid or comet flew over the lunar south pole, brushed by the mountain summits of Malapert and Mouton, and hit the lunar surface. The impact ejected high-energy streams of rock that carved two canyons that rival the size of Earth’s Grand Canyon. While the Grand Canyon took millions of years to form, the two grand canyons on the Moon were carved in less than 10 minutes.”

Those two canyons—named Vallis Schrödinger and Vallis Planck—are significant clues to that turbulent time in the Moon’s past. And, they’re impressive. Vallis Schrödinger is just under 300 kilometers long, 20 km wide, and 2.7 kilometers deep. Vallis Planck has two units. One is a deep canyon within the ejecta blanket of debris thrown out by the impact. The rest comprises a row of craters made as falling rocks were thrown out from the impact. They fell back to the Moon to create so-called “secondary craters.” The canyon part is about 280 kilometers deep, 27 km wide, and 3.5 km deep. The depth of both of these canyons surpasses the deep gorges of Earth’s Grand Canyon in Arizona.

Anatomy of an Impact and its Aftermath

The impactor probably slammed into the surface at nearly 55,000 kilometers per hour. The crash is what produced the enormous 320-kilometer-diameter Schrödinger impact basin. In the aftermath, the rocky debris scoured the deep canyons.

Schrödinger formed in the outer margin of the South Pole-Aitken (SPA) basin. At a diameter of about 2,400 km, it’s the largest and oldest impact basin on the Moon. The basin’s rim is about 300 km from the South Pole and within 125 km of the proposed exploration site for the Artemis mission.

The Schrödinger crater has a ~150-km diameter peak ring and the whole area is surrounded by a blanket of impact ejecta that splashed out in an irregular pattern up to 500 km away. The outermost crater ring resembles a circular mountain range and rises 1 to 2.5 km above the basin floor. It was produced by the collapse of a central uplift after the impact. After the impact, basaltic lava flows flooded the area. A large pyroclastic vent erupted more material onto the basin floor. That volcanic activity ended around 3.7 billion years ago.

Impact Anomalies

A careful analysis of the impact basin the canyons, and the ejecta surrounding the site by Kring and a team of scientists at the Lunar Planetary Laboratory, gives an idea of impact details. In a paper released about the site, the scientists discuss its features, plus some unusual finds. For example, the canyon rays don’t converge at the basin’s center as you might expect from typical impacts. They seem to come together in a different spot. That implies a point explosion impact.

Schrödinger peak-ring impact basin and two radiating canyons carved by impact ejecta. NASA\SVS\Ernest T. Wright. b Azimuthal Equidistant Projection of the Moon LRO LROC WAC Global Morphology Mosaic 100 centered on the Schrödinger basin, with the continuous ejecta blanket outlined and radial secondary crater rays (red). Vallis Schrödinger and Vallis Planck intersect near the southern rim of the basin (white point). The size of the point indicates the uncertainty. The projected bearing of the primary impactor (yellow) runs through the point of intersection and the basin center. A third unnamed feature extends in an uprange direction.

The location of the converging rays suggests that the incoming asteroid’s trajectory was about 33.5 west of north. The evidence also points to a distributed impact. That could mean the impactor came in at a low angle. Or, it’s also possible that secondary ejecta from the impact also came in at low angles. There are many secondary craters in the area which help explain the possibilities. Continued analysis will help explain the huge amounts of energy released in the event. Gareth Collins, one of Kring’s team members, said, “The Schrödinger crater is similar in many regards to the dino-killing Chicxulub crater on Earth. By showing how Schrödinger’s km-deep canyons formed, this work has helped to illuminate how energetic the ejecta from these impacts can be.”

Future Exploration

Of course, these rays and the impact basin will end up as great exploration points for NASA’s upcoming Artemis missions. Right now, the evidence from the ejecta blanket points to the fact that there’s an uneven distribution, particularly in the area where the first missions are planned. That will allow astronauts and robotic probes to reach underlying samples of the Moon’s primordial crust without having to dig through rocks of a younger age.

Since the basin is the second-youngest basin on the Moon, the impact melted rocks will be a great way to test the actual age of the impact. The general understanding is that some 3.8 billion years ago, the Moon (and Earth) experienced a great many of these collisions. This epoch was the Late Heavy Bombardment, thought to have lasted up to 200 million years. The continual impacts during this time scarred the surfaces of the rocky planets and the Moon, as well as asteroids. Lunar rocks created as a result of lava flows at that time will open a window into their ages and mineralogy, especially compared to other, older rock formations. They should also improve our understanding of that period of solar system history. In particular, it can help scientists characterize the impacts on Earth that affected not just the surface, but its life forms.

For More Information

Grand Canyons on the Moon (journal article)
Grand Canyons on the Moon

The post The Moon has Two Grand Canyons, Carved in Minutes by an Asteroid Impact appeared first on Universe Today.

How would detecting methane help astronomers identify if exoplanets, or even exomoons, have life as we know it, or even as we don’t know it? This is what a recent study published in The Astronomical Journal hopes to address as a team of researchers led by the NASA Goddard Space Flight Center investigated how a method called BARBIE (Bayesian Analysis for Remote Biosignature Identification on exoEarths) could be used on a future space mission to detect methane (CH4) on Earth-like exoplanets in optical (visible) and near-infrared (NIR) wavelengths. This study builds on past studies using BARBIE, known as BARBIE 1 and BARBIE 2, and has the potential to help scientists and engineers develop new methods for finding life beyond Earth and throughout the cosmos.

Here, Universe Today discusses this incredible study with Natasha Latouf, who is a PhD Candidate in the Department of Physics and Astronomy at George Mason University and lead author of the study, regarding the motivation behind the study, significant results, potential follow-up studies, next steps for BARBIE, the significance of detecting methane on Earth-like exoplanets, and if Natasha thinks we’ll ever find life on Earth-like exoplanets. Therefore, what was the motivation behind the study?

Latouf tells Universe Today, “We developed the BARBIE methodology in order to quickly investigate large amounts of parameter space and make informed decisions about the resultant observational trade-offs. Methane is a key contextual biosignature that we would be very interested in detecting, especially with other biosignatures like O2.”

As its name states, BARBIE used what’s known as a Bayesian inference, which is a statistical method employed to determine data probability outcomes based on a given input of data, meaning the probabilities change based on additional data input. As noted, this work builds off previous studies involving BARBIE, with those investigating parameters including observing exoplanets in optical wavelengths with planetary parameters including surface pressure, surface albedo, gravity, along with water (H20), oxygen (O2), and ozone (O3) abundance. However, those results indicated that only oxygen-rich atmospheres were observable in optical wavelengths, with the authors noting the parameters were too limited. With this work, known as BARBIE 3, the team added NIR wavelengths and CH4 to the parameters to broaden the parameters for more desirable results. Therefore, what were the most significant results from this study?

“The most significant results from this study is the interesting interplay between H2O and CH4 in the near-infrared (NIR),” Latouf tells Universe Today. “While we knew that the spectral features H2O and CH4 overlap heavily in the NIR, and would probably cause some issues with detectability, what we didn’t realize was how much that effect mattered. In fact, we find that at sufficiently high CH4, the signal-to-noise ratio (SNR) required to strongly detect H2O shoots up, and the same vice versa. Essentially, we need to be careful before claiming a planet has no H2O or CH4, because if both are present, we might be missing one! There are follow up studies happening currently, led by my fantastic post-bac Celeste Hagee, studying how the detectability of biosignatures in the NIR changes if we add CO2 into the mix!”

Along with building off previous BARBIE studies, this study focuses on contributing to the planned NASA Habitable Worlds Observatory (HWO) mission, which was recommended by National Academies of Sciences, Engineering, and Medicine (NASEM) Decadal Survey on Astronomy and Astrophysics 2020 and is currently planned to launch sometime in the 2040s. The goal of HWO will be to analyze 25 potentially habitable exoplanets, which contrast past and current exoplanet-hunting missions like NASA’s Kepler and NASA’s TESS (Transiting Exoplanet Survey Satellite) missions, respectively, whose objectives were to locate and identify as many exoplanets as possible.

Artist’s rendition for NASA’s Habitable Worlds Observatory, which is slated to launch in the 2040s with the goal of analyzing 25 potentially habitable exoplanets for biosignatures along with conducting other incredible science about our place in the cosmos. (Credit: NASA’s Goddard Space Flight Center Conceptual Image Lab)

HWO will use a combination of the direct imaging method to find the exoplanets and its spectroscopy instruments to analyze their respective atmospheres for biosignatures, specifically oxygen and methane. Along with identifying and analyzing potential habitable exoplanets, the other science goals include galaxy growth, element evolution from the Big Bang until now, and our solar system and its place in the universe. Therefore, what next steps need to be taken for BARBIE to become a reality on a future exoplanet imaging mission like HWO?

“The reason why BARBIE is useful is because it provides a huge swath of information about lots of parameter space very quickly – that means we can use that data to build future telescopes!” Latouf tells Universe Today. “For instance, if we’re trying to understand whether we need a 20% or a 40% coronagraph in order to strongly detect biosignatures in the optical regime, we can look at how the 20% and 40% influences detection of biosignatures, and from there make the decision on whether the science benefit of a 40% is worth the increased cost.”

This isn’t the first time scientists have postulated that methane might be a key indicator of life on exoplanets, as a 2022 study published in the Proceedings of the National Academy of Sciences (PNAS) discussed how atmospheric methane should be considered an exoplanet biosignature and be targeted by space telescopes like NASA’s James Webb Space Telescope (JWST). Within our own solar system, methane is a key component of Saturn’s largest moon, Titan, with researchers hypothesizing that its crust could contain methane. Additionally, Mars experiences seasonal changes in methane gases that keep scientists puzzled regarding its origin. Therefore, what is the significance of identifying methane on Earth-like exoplanets?

Latouf tells Universe Today, “CH4 is a contextual biosignature – if we find sufficient amounts of CH4 and O2 in an atmosphere together, it means the atmosphere is in disequilibrium. That means that there must be something PRODUCING those levels of CH4 and O2, and depending on the abundances of each, the signs would point to some form of life behind that production.”

This study comes as the number of confirmed exoplanets currently totals 5,832 with 212 being designated as terrestrial (rocky) exoplanets, or exoplanets that are Earth-sized or smaller. A primary example of terrestrial exoplanets includes the TRAPPIST-1 system that resides just over 40 light-years from Earth and is currently hypothesized to host seven Earth-sized exoplanets with at least three orbiting in its star’s habitable zone, which is the right distance from the star to support surface liquid water like Earth.

The closest known terrestrial exoplanet to Earth is Proxima Centauri b, which is 4.24 light-years from Earth and orbits within its star’s HZ despite its orbit only being 11.2 days. However, this also means Proxima Centauri b is blasted by ultraviolet radiation, meaning its surface might not be suitable for life as we know it. Therefore, does Latouf believe we will ever find life on Earth-like exoplanets and which Earth-like exoplanets are particularly interesting to her?

“In my opinion, I think that we will,” Latouf tells Universe Today. “Will that happen in my lifetime? That I’m not sure of – but I do believe we’re going to find life eventually! Although it’ll sound boring the most Earth-like planet I’m interested in is…Earth. We have this wonderful gift in this planet, with all the exact right conditions. We need to be making sure we’re preserving it and understanding our own planet before we dive into the search for others!”

For now, BARBIE remains on the drawing board, but it demonstrates the tireless commitment of the scientific community to improve upon previous designs with the goal of answering whether life exists beyond Earth and throughout the cosmos. Going forward, the authors note that future work will continue to enhance BARBIE’s capabilities, including detecting all molecules across HWO’s entire wavelength range like ultraviolet in addition to optical and NIR. They also plan to test whether coronagraph detectors, which block light from a star to both reveal and improve exoplanet analysis, are suitable for identifying molecules in an exoplanet’s atmosphere.

Latouf concludes by telling Universe Today, “I want to emphasize that it’s very easy to see a completed paper and think to yourself, especially as an early career, “I could never do that.” BARBIE was a project that was created by a team – sure, I put my special branding on it and did the work, but the project was born of open collaboration and communication. The process of doing the work for BARBIE1, 2, and 3 took about 3.5 years, and many, many setbacks. This work is hard, it’s not easy, and no one finds it easy. All this to say – if you’re working on something, and looking at others thinking you can’t do it like they can, just know: they’re learning and growing too, and science is never as easy as it looks.”

Is methane the correct biosignature to identify life as we know it on exoplanets and how will BARBIE help the continued search for life beyond Earth in the coming years and decades? Only time will tell, and this is why we science!

As always, keep doing science & keep looking up!

The post Is Methane the Key to Finding Life on Other Worlds? appeared first on Universe Today.

In the more than 60 years since the Space Age began, humans have sent more than 6,740 rockets to space. According to the ESA’s Space Debris Office, this has resulted in 56,450 objects in orbit; about 36,860 of these objects are regularly tracked and maintained in a catalog, while 10,200 are still functioning. The rest is a combination of spent rocket stages, defunct satellites, and pieces of debris caused by unused propellant exploding and orbital collisions. This is leading to a cascade effect known as Kessler Syndrome, where the amount of debris in orbit will lead to more collisions and more debris.

What’s worse, the situation is only projected to get worse since more launches are expected with every passing year. Last year, space agencies and commercial space companies conducted a record-breaking 263 launches, with the U.S. (158) and China (68) leading the way. And with future break-ups occurring at historic rates of 10 to 11 per year, the number of debris objects in orbit will continue to increase. According to a new study by a team from the University of British Columbia (UBC), this also means that debris falling to Earth will have a 1 in 4 chance per year of entering busy airspace.

Ewan Wright, a doctoral student in UBC’s Interdisciplinary Studies Graduate Program, led the research. He was joined by Associate Professor Aaron Boley of the UBC Department of Physics and Astronomy and the co-director of The Outer Space Institute (OSI) at UBC, and Professor Michael Byers, the Canada Research Chair in Global Politics and International Law at the UBC Department of Political Science. The paper detailing their findings, “Airspace closures due to reentering space objects,” recently appeared in Scientific Reports, a journal maintained by Nature Publishing.

Artist’s impression of the orbital debris problem. Credit: UC3M

Traditionally, the discussion of space junk and the Kessler Syndrome has focused on how debris in orbit will pose a hazard for future satellites, payloads, and current and future space stations. In 2030, NASA and its many partnered space agencies plan to decommission the International Space Station (ISS) after thirty years of continuous service. However, this situation will also mean that more debris will be deorbiting regularly, not all of which will completely burn up in Earth’s atmosphere.

While the chance of debris hitting an aircraft is very low (one in 430,000, according to their paper), the UBC team’s research highlights the potential for disruption to commercial air flights and the additional costs it will lead to. The situation of more launches and more hazards is illustrated perfectly by the “rapid unscheduled disassembly” (RUD) of the Starship on January 16th, during its seventh orbital flight test. The explosion, which happened shortly after the prototype reentered Earth’s atmosphere, caused debris to rain down on the residents of the Turks and Caicos. Said Wright in a UBC News release:

“The recent explosion of a SpaceX Starship shortly after launch demonstrated the challenges of having to suddenly close airspace. The authorities set up a ‘keep out’ zone for aircraft, many of which had to turn around or divert their flight path. And this was a situation where we had good information about where the rocket debris was likely to come down, which is not the case for uncontrolled debris re-entering the atmosphere from orbit.”

A similar situation happened in 2022 when the spent stages of a Chinese Long March 5B (CZ-5B) weighing about 20 metric tons (22 U.S. tons) prompted Spanish and French aviation authorities to close parts of their airspace. If spent stages and other payloads have a low enough orbit, they can reenter Earth’s orbit uncontrolled, and large portions may make it to the ground. In addition to the record number of launches last year, there were also 120 uncontrolled rocket debris re-entries while more than 2,300 spent rocket stages are still in orbit.

Debris from the SpaceX Starship launched on January 16th, spotted over the Turks and Caicos Islands.
Credit: Marcus Haworth/Reuters

According to the International Air Transport Association, passenger numbers are expected to increase by almost 7% this year. With rocket launches and commercial flights increasing at their current rate, Wright and his colleagues say that action must be taken to mitigate the potential risks. As part of their study, the team selected the busiest day and location for air traffic in 2023, which was in the skies above Denver, Colorado – with one aircraft for every 18 square km (~7 mi2). They then paired this to the probability of spent rock stages reentering Earth’s atmosphere (based on a decade of data) above the flights.

With this as their peak, they calculated the probability of rocket debris reentering the atmosphere over different air traffic density thresholds. Their results showed that for regions experiencing 10% peak air traffic density or higher, there was a 26% chance of deorbited rocket debris entering that airspace. “Notably, the airspace over southern Europe that was closed in 2022 is only five percent of the peak,” said Wright. “Around the world, there is a 75-per-cent chance of a re-entry in such regions each year.”

At present, whenever orbital debris reenters the atmosphere around busy airspace, aviation authorities will respond by diverting flight paths, closing airspace, or taking the risk of allowing flights to continue. “But why should authorities have to make these decisions in the first place? Uncontrolled rocket body re-entries are a design choice, not a necessity,” said Dr. Boley. “The space industry is effectively exporting its risk to airlines and passengers.”

One possibility is to design rocket stages to reenter the atmosphere in a controlled way so they can crash into the ocean far away from busy air traffic lanes. However, this solution requires collective international action. “Countries and companies that launch satellites won’t spend the money to improve their rocket designs unless all of them are required to do so,” said Dr. Byers. “So, we need governments to come together and adopt some new standards here.”

Further Reading: UBC, Scientific Reports

The post Space Junk Could Re-Enter the Atmosphere in Busy Flight Areas appeared first on Universe Today.

The idea of Dyson Sphere’s has been around for decades. When Freeman Dyson explored the concept he acknowledged that they may not be a physical sphere but could be a swarm of satellites in a spherical configuration around a star. The challenge with a solid sphere is that its orbit will not be stable leading to its destruction. A new paper casts a new view on that though and proposes a way that a rigid sphere could be stable after all. The idea suggests that a binary star system, where the mass ratio between the two objects is small, the sphere may be stable. 

The Dyson Sphere is a theoretical megastructure that was first proposed by physicist Freeman Dyson in 1960 as a method to harness the energy output of a star. The concept may take the form of a massive shell or a swarm, or network of solar-collecting satellites circling a star to capture and utilise its energy, potentially providing virtually limitless power. Dyson acknowledged that the construction of a solid sphere around a star is impractical due to immense material and stability challenges, a more feasible design involves a Dyson swarm—a collection of orbiting solar power stations. 

Freeman Dyson speak at the Long Now Foundation.

The idea of a solid sphere has taken a back seat over recent years and indeed studies have focussed on searches for satellite swarms. The acceptance that such a solid structure is not stable has been supported by other studies. In 1856, James Clark Maxwell showed that Saturn’s rings too, could not possibly be a solid uniform structure. The interaction of gravity between the ring and the planet would result in instability. The same was thought to be true for a Dyson Sphere. That was until Colin R McInnes published his findings in the monthly notices of the Royal Astronomical Society. 

Saturn and its system of rings, acquired by the Cassini probe. Credit: NASA/JPL-Caltech

McInnes argues that a solution lies within the circular restricted three-body problem. This is a classical problem from celestial mechanics. At its core, it describes the motion of a small body (such as an asteroid) under the gravitational influence of two larger objects (like the Sun and Jupiter) which are in circular orbits around their common centre of mass. The presence of the smaller object, which has negligible mass has no significant impact on the motion of the two larger bodies. 

In such a system, there would be five equilibrium points known as Lagrange points. Two of these will be unstable but two of them (L4 and L5) will be stable but only if the mass ratio is small as in Jupiter and the Sun for example. Here, an object will remain in a stable orbit. There are extensions and more complicated models to consider where for example radiation pressure has an impact on the stability of a system.

McInnes finds that there are configurations that could be stable for a sphere or ring after all but only under specific conditions. The first occurs if the two primary masses in the system are in orbit around their common centre of mass and a large uniform ring encloses the smaller mass. Of perhaps more interest is that McInnes suggests even a sphere could be stable if it encloses the smaller of the two masses. 

The results of the study reveal an enticing glimpse into a universe where Dyson sphere’s may not be just restrained to science fiction. That there may be stellar systems scattered across the cosmos where advanced civilisations have harnessed the energy from one of their local stars. 

Source : Ringworlds and Dyson spheres can be stable 

The post There’s a Way to Make Ringworlds and Dyson Spheres Stable appeared first on Universe Today.

Roughly 4.6 billion years ago, the Sun was born from the gas and dust of a nebula that underwent gravitational collapse. The remaining gas and dust settled into a protoplanetary disk that slowly accreted to form the planets, including Earth. About 4.5 billion years ago, our planet was impacted by a Mars-sized body (Theia), which led to the formation of the Moon. According to current theories, water was introduced to Earth and the inner planets by asteroids and comets that permeated the early Solar System.

The timing of this event is of major importance since the introduction of water was key to the origin of life on Earth. Exactly when this event occurred has been a mystery for some time, but astronomers generally thought it had arrived early during Earth’s formation. According to a recent study by a team led by scientists from the University of Rutgers-New Brunswick, water may have arrived near “late accretion” – the final stages of Earth’s formation. These findings could seriously affect our understanding of when life first emerged on Earth.

The team was led by Katherine Bermingham, an associate professor in the Department of Earth and Planetary Sciences at Rutgers-New Brunswick and the University of Maryland. She was joined by researchers from Clemson University, the Research Centre for Astronomy and Earth Sciences (CSsFK), the Department of Lithospheric Research, the Centre for Planetary Habitability (PHAB), and the Institute for Earth Sciences. Their findings are described in a paper, “The non-carbonaceous nature of Earth’s late-stage accretion,” in Geochimica et Cosmochimica Acta.

Artist’s impression of the giant impact that shaped the Earth and created the Moon.
Credit: NASA/JPL-Caltech.

According to what scientists have learned from life on Earth, three ingredients are essential to putting the process in motion. These are water, energy, and the basic building blocks of organic chemicals – carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur – collectively called CHNOPS. As a cosmogeochemist, Bermingham and her associates are dedicated to the study of the chemical composition of matter in the Solar System. This largely consists of analyzing Earth rocks and materials deposited by meteorites and other extraterrestrial sources.

In so doing, they hope to learn more about the origin and evolution of the Solar System and its rocky planets. A major aspect of this is knowing when and where the basic ingredients for life originated and how they found their way to Earth. For their study, Birmingham and her team examined meteorites obtained from the Smithsonian National Museum of Natural History that belong to the “NC” group. These meteorites’ composition suggests they formed in the inner Solar System, where conditions were drier.

This sets them apart from the “CC” group, which likely formed in the outer Solar System, where water and other volatiles were more abundant. The team extracted isotopes of molybdenum from these meteorites – a trace mineral essential for human health – and analyzed them using ionization spectrometry and a new analytical method they developed. This element is thought to have been deposited on Earth at about the same time the Moon formed, which was thought to have deposited a significant amount of the Earth’s water. As Birmingham explained in a Rutgers University press release:

“When water was delivered to the planet is a major unanswered question in planetary science. If we know the answer, we can better constrain when and how life developed. The molybdenum isotopic composition of Earth rocks provides us with a special window into events occurring around the time of Earth’s final core formation, when the last 10% to 20% of material was being assembled by the planet. This period is thought to coincide with the Moon’s formation.”

A piece of iron meteorite Campo del Cielo, one of the samples measured in the study. Credit: Katherine Bermingham

They then compared the composition of these meteors’ isotopes to Earth rocks obtained by field geologists from Greenland, South Africa, Canada, the United States, and Japan. Their analysis showed that the Earth rocks were more similar to meteorites originating in the inner Solar System (NC). As Birmingham said:

“Once we gathered the different samples and measured their isotopic. compositions, we compared the meteorites signatures with the rock signatures to see if there was a similarity or a difference. And from there, we drew inferences. We have to figure out from where in our solar system Earth’s building blocks – the dust and the gas – came and around when that happened. That’s the information needed to understand when the stage was set for life to begin.”

The finding is significant since it indicates that Earth did not receive as much water from the Moon-forming impact as previously theorized. Instead, the data supports the competing school of thought that water was delivered to Earth in smaller portions late in its formation history and after the Moon was formed. “Our results suggest that the Moon-forming event was not a major supplier of water, unlike what has been thought previously,” said Bermingham. “These findings, however, permit a small amount of water to be added after final core formation, during what is called late accretion.”

Further Reading: Rutgers University, Geochimica et Cosmochimica Acta

The post Water Arrived in the Final Stages of Earth's Formation appeared first on Universe Today.