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Huge crater in India hints at major meteorite impact 4000 years ago

New Scientist Feed - Tue, 03/26/2024 - 1:00am
The Luna structure, a 1.8-kilometre-wide depression in north-west India, may have been caused by the largest meteorite to strike Earth in the past 50,000 years
Categories: Science

Your nationality may influence how much you talk with your hands

New Scientist Feed - Mon, 03/25/2024 - 10:00pm
When recounting an episode of the children's TV show Pingu, people from Italy made an average of 22 gestures per 100 words, compared with 11 for Swedish people
Categories: Science

NASA’s VERITAS Mission Breathes New Life

Universe Today Feed - Mon, 03/25/2024 - 7:29pm

In a win for planetary scientists, and planetary geologists in particular, it was announced at the recent 55th Lunar and Planetary Science Conference (LPSC) in Texas earlier this month that NASA’s VERITAS mission to the planet Venus has been reinstated into NASA’s Fiscal Year 2025 (FY25) budget with a scheduled launch date of 2031, with the unofficial announcement coming on the first day of the conference, March 11, 2024, and being officially announced just a few days later. This comes after VERITAS experienced a “soft cancellation” in March of last year when NASA revealed its FY24 budget, providing VERITAS only $1.5 million, which was preceded by the launch of VERITAS being delayed a minimum of three years due to findings from an independent review board in November 2022.

VERITAS is back in the budget!! ??? The project will get going full swing this fall (FY25). We’re looking at a 31 launch (TBC). Thanks to everyone who’s supported our return to Venus!! It’s going to be fabulous ?

— Sue Smrekar (@SueSmrekar) March 11, 2024 Dr. Sue Smrekar, who is the Principal Investigator for the VERITAS mission, announcing during LPSC 2024 that VERITAS has been reinstated.

Here, Universe Today speaks with Dr. Paul Byrne, who is an Associate Professor of Earth, Environmental, and Planetary Sciences at Washington University in St. Louis, and a huge proponent of exploring Venus, about his thoughts on VERITAS being reinstated, the alleged events that led to VERITAS’ reinstatement, his experience between VERITAS being postponed to now, and his thoughts on what science VERITAS hopes to accomplish at Venus. So, what are his thoughts on VERITAS being reinstated?

“First and foremost, it’s relief,” Dr. Byrne tells Universe Today. “Although VERITAS wasn’t cancelled per se, we in the planetary community weren’t sure if or where VERITAS would be reinstated. Although it’s disappointing to have a selected mission be delayed, it’s a very positive sign that VERITAS is back in the budget. Of course, there’s a flip side to this development: the mission’s stablemate, DAVINCI, has itself been delayed. It’s clear that the prevailing budget situation at NASA is very tough right now, and lots of missions are feeling it. Unfortunately, with two Venus missions in the pipeline, the Venus community is feeling this budget toughness most acutely.”

After years of being proposed as a NASA Discovery mission, VERITAS was officially selected in June 2021, along with DAVINCI (previously known as DAVINCI+) to explore the second planet from the Sun like never before. While VERITAS will be tasked with producing new surface maps of Venus, DAVINCI was tasked with conducting atmospheric science, as debate continues over the potential habitability of Venus’ atmosphere. With an initial scheduled launch date between 2028 and 2030, the November 2022 findings pushed this back to 2031, only to result in the “soft cancellation” just months later. With the planetary science community pushing for VERITAS to be reinstated over the last 12 months, what led to VERITAS being reinstated?

“A major part of it was, in my view, strong advocacy not only by the Venus community but by the planetary science community at large,” Dr. Byrne tells Universe Today. “Other advisory groups—volunteer groups charged with collating and representing to NASA the needs of a given portion of the planetary science community—voiced very loud, strong support for VERITAS beyond just the Venus community, in a wonderful example of community-wide support. Groups such as The Planetary Society also lent their voice to supporting VERITAS. That advocacy was noticed by NASA HQ and by Congress, which played no small role in getting VERITAS back into the budget.”

While not officially a member of the VERITAS mission team, Dr. Byrne has a myriad of publications about Venus, including as a co-author on five LPSC 2024 studies that discussed lava flow cooling, Venus’ potential habitability as an analog for other planets, predicting tectonic activity, predicting future volcanic activity, and current active volcanism. Additionally, Dr. Byrne has expressed his continued support via social media for both the second planet from the Sun and the VERITAS and DAVINCI missions throughout their respective journeys, and specifically when they were selected in June 2021. Therefore, what kind of emotional roller coaster has he experienced between VERITAS being canceled and now?

“It’s so hard to see a mission being selected for a science target NASA hasn’t been to in forty years, only for it to be postponed through no fault of the mission team itself,” Dr. Byrne tells Universe Today. “And it’s wonderful that we now know VERITAS will fly, even if it’s later than originally planned. But I’m keenly aware, as someone who’s not a member of the VERITAS team, that the highs and lows I’ve experienced are nothing compared with those of the team itself, who put their heart and soul (and at least three attempts!) to get VERITAS selected. Better late than never, but better on time than late. Still, we make do with the circumstances we face!”

As Dr. Byrne alluded to, the last NASA mission to Venus was the Magellan spacecraft, which was launched on May 4, 1989, from the Space Shuttle Atlantis during the STS-30R mission and arrived at Venus on August 10, 1990. Over the course of the next four years, Magellan used its synthetic aperture radar to map the entire surface of Venus since the extreme thickness of Venus’ clouds prevents direct imaging of the surface.

After Magellan’s first imaging cycle that lasted 243 days, it successfully mapped 83.7 percent of Venus’ surface, which increased to 96 percent after its second cycle and completed its mission at 98 percent after its third cycle. As a result, Magellan images identified a myriad of features across the Venusian surface, including volcanic evidence, tectonic activity, lava channels, pancake-shaped domes, and stormy winds across the surface. Therefore, with VERIATS equally tasked with mapping Venus’ surface, what science does VERITAS hope to achieve at Venus?

“VERITAS will carry a radar to Venus to obtain the most comprehensive, accurate, and highest-resolution radar image and topographic data ever acquired for the second planet,” Dr. Byrne tells Universe Today. “VERITAS will also be able to acquire spectral measurements of the surface in the infrared, offering us new insight into the composition of the planet’s surface materials. Moreover, the topographic and geodetic data VERITAS will return will in turn be used to help calibrate data from DAVINCI and the ESA EnVision mission, too.”

What new discoveries will VERITAS make about Venus 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 NASA’s VERITAS Mission Breathes New Life appeared first on Universe Today.

Categories: Science

Research lights up process for turning CO2 into sustainable fuel

Matter and energy from Science Daily Feed - Mon, 03/25/2024 - 5:16pm
Researchers have successfully transformed CO2 into methanol by shining sunlight on single atoms of copper deposited on a light-activated material, a discovery that paves the way for creating new green fuels.
Categories: Science

Life Might Be Difficult to Find on a Single Planet But Obvious Across Many Worlds

Universe Today Feed - Mon, 03/25/2024 - 3:15pm

If we could detect a clear, unambiguous biosignature on just one of the thousands of exoplanets we know of, it would be a huge, game-changing moment for humanity. But it’s extremely difficult. We simply aren’t in a place where we can be certain that what we’re detecting means what we think or even hope it does.

But what if we looked at many potential worlds at once?

It’s assumptions that plague us. Every chemical we detect in an exoplanet atmosphere, even with the powerful JWST, is accompanied by a set of assumptions. We simply don’t know enough yet for it to be any other way. This puts us in a difficult place, considering the magnitude of the question we’re trying to answer: is there life beyond Earth?

“A fundamental goal of astrobiology is to detect life outside of Earth,” write the authors of a new paper. It’s titled “An Agnostic Biosignature Based on Modeling Panspermia and Terraformation,” and it’s available on the pre-press site arxiv.org. The authors are Harrison B. Smith and Lana Sinapayen. Smith is from the Earth-Life Science Institute at the Tokyo Institute of Technology in Japan, and Sinapayen is from the Sony Computer Science Laboratories in Kyoto, Japan.

The fundamental goal that the pair of authors give voice to is a difficult one to reach. “This proves to be an exceptional challenge outside of our solar system, where strong assumptions must be made about how life would manifest and interact with its planet,” the authors explain. We only know how Earth’s biosphere works, and we’re left to assume what similarities there might be with other planets. We don’t have any consensus about how biospheres might be able to work. We’re not completely ignorant, as chemistry and physics make some things possible and others impossible. But we’re not an authority on biospheres.

Scientists are pretty good at modelling things and trying to generate useful answers, as well as generating relevant questions they might not have thought of without models. In this work, the pair of authors took a different approach to understanding life on other worlds and what effort we can make to detect it.

“Here we explore a model of life spreading between planetary systems via panspermia and terraformation,” the authors write. “Our model shows that as life propagates across the galaxy, correlations emerge between planetary characteristics and location and can function as a population-scale agnostic biosignature.”

The word ‘agnostic’ is key here. It means that they’re aiming to detect a biosignature that’s independent of the assumptions we’re normally saddled with. “This biosignature is agnostic because it is independent of strong assumptions about any particular instantiation of life or planetary characteristic—by focusing on a specific hypothesis of what life may do rather than what life may be,” the authors explain.

This approach is different. They analyze planets by their observed characteristics and then cluster them based on those observations. Then, they examine the spatial extent of the clusters themselves. That leads to a way to prioritize individual planets for their potential to harbour life.

Panspermia and terraforming play key roles. We know that rocks can travel between worlds, and that’s called lithopanspermia. Powerful impacts on Mars lofted rocks into space, some of which eventually fell to Earth. If dormant organisms like spores could survive the journey, it’s at least feasible that life could spread this way.

Panspermia is the idea that life is spread throughout the galaxy, or even the Universe, by asteroids, comets, and even minor planets. Credit: NASA/Jenny Mottor

Terraforming is self-explanatory for the most part. It’s the effort to engineer a world to be more habitable. If there are other technological, space-faring civilizations out there, one useful working assumption is that they’ll eventually terraform other worlds if they last long enough. In any case, even non-technological life can purposefully alter its environment. (Sit and watch beavers sometime.)

The authors make an interesting point regarding panspermia and terraforming. They’re both things that life already does, kind of. “Ultimately, our postulates of panspermia and terraformation are merely well-understood hallmarks of life (proliferation via replication and adaptation with bi-directional environmental feedback), escalated to the planetary scale, and executed on an interstellar scale,” they write.

The authors’ model shows that the way planets are distributed around stars, along with their other characteristics, could be evidence of life without even attempting to detect chemical biosignatures. This is the agnostic part of their work. It’s more powerful than a one-planet-at-a-time struggle to detect biosignatures, as plagued as that effort is by assumptions. Single planets with detected biosignatures can always be explained away by something anomalous. But that’s harder to do in this agnostic method.

“Hypothesizing that life spreads via panspermia and terraformation allows us to search for biosignatures while forgoing any strong assumptions about not only the peculiarities of life (e.g., its metabolism) and planetary habitability (e.g., requiring surface liquid water) but even the potential breadth of structure and chemical complexity underpinning living systems,” the authors explain.

This figure from the study helps illustrate the authors’ work. A shows a target planet selection, where an initial planet and its composition are randomly selected. This planet represents a terraformed parent planet. B shows the simulation run beginning with the initial parent planet, showing how nearby planets will be terraformed to more closely match the parent planet. C shows how each terraformed planet will retain some of its differences, about 10% in the researchers’ model. Image Credit: Smith and Sinapayen, 2024.

We’re accustomed to thinking about specific chemicals, and the types of atmospheres exoplanets have to determine the presence of biosignatures. But that’s not how this works. This model is agnostic, so it’s not really about specific chemical biosignatures. It’s more about the patterns and clusters we could detect in populations of planets that could signal the presence of life via panspermia and terraforming.

Terraformed planets can be identified from their clustering, the authors claim. That’s because when they’re terraformed, the planets need to reflect the originating planet.

This figure from the research shows how simulated terraformed planets would appear clustered on a graph. This is a projection of 3D planet locations in the 2D X-Y plane and the earliest time step where the researchers detect a cluster of planets meeting their selection criteria. True terraformed planets have a blue fill, while planets detected by their selection method have a red outline. Image Credit: Smith and Sinapayen, 2024.

There are obstacles to this method that limit its usefulness and implementation. According to the authors, they need to identify “… specific ways in which better understanding astrophysical and planetary processes would improve our ability to detect life,” the authors write.

But even without more specifics, the method is thought-provoking and creative. In the end, the authors’ model and method lead to a novel way to think about life’s hierarchies and how these hierarchies might be replicated on other planets.

If this method is strengthened and more fully developed, who knows what it might lead to?

The post Life Might Be Difficult to Find on a Single Planet But Obvious Across Many Worlds appeared first on Universe Today.

Categories: Science

Engineering household robots to have a little common sense

Matter and energy from Science Daily Feed - Mon, 03/25/2024 - 2:24pm
Engineers aim to give robots a bit of common sense when faced with situations that push them off their trained path, so they can self-correct after missteps and carry on with their chores. The team's method connects robot motion data with the common sense knowledge of large language models, or LLMs.
Categories: Science

Engineering household robots to have a little common sense

Computers and Math from Science Daily Feed - Mon, 03/25/2024 - 2:24pm
Engineers aim to give robots a bit of common sense when faced with situations that push them off their trained path, so they can self-correct after missteps and carry on with their chores. The team's method connects robot motion data with the common sense knowledge of large language models, or LLMs.
Categories: Science

GPT-4 for identifying cell types in single cells matches and sometimes outperforms expert methods

Computers and Math from Science Daily Feed - Mon, 03/25/2024 - 2:24pm
GPT-4 can accurately interpret types of cells important for the analysis of single-cell RNA sequencing -- a sequencing process fundamental to interpreting cell types -- with high consistency compared to that of time-consuming manual annotation by human experts of gene information.
Categories: Science

Pairing crypto mining with green hydrogen offers clean energy boost

Matter and energy from Science Daily Feed - Mon, 03/25/2024 - 2:24pm
Pairing cryptocurrency mining -- notable for its outsize consumption of carbon-based fuel -- with green hydrogen could provide the foundation for wider deployment of renewable energy, such as solar and wind power, according to a new study.
Categories: Science

Pairing crypto mining with green hydrogen offers clean energy boost

Computers and Math from Science Daily Feed - Mon, 03/25/2024 - 2:24pm
Pairing cryptocurrency mining -- notable for its outsize consumption of carbon-based fuel -- with green hydrogen could provide the foundation for wider deployment of renewable energy, such as solar and wind power, according to a new study.
Categories: Science

With a new experimental technique, engineers probe the mechanisms of landslides and earthquakes

Matter and energy from Science Daily Feed - Mon, 03/25/2024 - 2:24pm
Researchers developed a method for 3D experiments that can reveal how forces are transmitted through granular materials, and how the shapes of the grains can dramatically change the outcomes. This could lead to better ways of understanding how landslides are triggered, and how to control the flow of granular materials in industrial processes.
Categories: Science

Brown Dwarf Pairs Drift Apart in Old Age

Universe Today Feed - Mon, 03/25/2024 - 1:09pm

The only thing worse than drifting through space for an eternity is doing it alone. Observations with the Hubble Space Telescope show that brown dwarfs that once had companions suffer that fate. Binary brown dwarfs that were once bound to each other tend to drift apart as time passes.

Brown dwarfs are one of Nature’s genre-busters. They refuse to be pigeonholed into our definitions. They’re neither stars nor planets and are sometimes referred to as failed stars. They gathered too much mass to be called planets but not enough to be called stars. They live in a kind of twilight zone, where they go about their business fusing only deuterium. This fusion is enough to emit some light and warmth but nothing that rivals an actual main sequence star.

Brown dwarfs are too big to be planets but not quite massive enough to be stars. Credit: NASA/JPL-Caltech

Brown dwarfs are not necessarily brown in colour. Their name comes from their size. They’re in between white dwarf stars and “dark” planets, if that makes sense. Brown dwarfs fade over time as they deplete their deuterium. The warmest ones are red or orange, and the cooler ones are magenta or even black to our eyes. Astronomers think brown dwarfs will cool down forever.

Most stars are in binary pairs, and brown dwarfs are no exception. Up to 85% of stars in the Milky Way are in binary pairs, according to some research. But the Hubble shows that when it comes to brown dwarfs, divorce is more common than in Hollywood.

In a survey of stars in our solar neighbourhood, the HST didn’t find any binary brown dwarfs with widely separated companions. That implies that brown dwarfs can’t maintain their binary relationships, probably because they’re simply not massive enough.

“This is the best observational evidence to date that brown dwarf pairs drift apart over time,” said Clémence Fontanive, the lead author of a new paper. “We could not have done this kind of survey and confirmed earlier models without Hubble’s sharp vision and sensitivity.”

The new paper is in the Monthly Notices of the Royal Astronomical Society. Its title is “An HST survey of 33 T8 to Y1 brown dwarfs: NIR photometry and multiplicity of the coldest isolated objects.” The lead author is Clémence Fontanive from the Trottier Institute for Research on Exoplanets, Université de Montréal, Canada. Brown dwarfs occupy spectral types M, L, T, and Y, and the numbers in the title are sub-types.

“Our survey confirms that widely separated companions are extremely rare among the lowest-mass and coldest isolated brown dwarfs, even though binary brown dwarfs are observed at younger ages. This suggests that such systems do not survive over time,” said lead author Fontanive.

The researchers worked with a set of 33 nearby ultracool brown dwarfs, a sample large enough to be statistically significant. The survey was designed to be deeply sensitive to low-mass objects that could be companions. Though the survey unearthed some potential companions for some of the brown dwarfs, further analysis showed they’re background objects.

The fact that they detected no binary companions allowed the researchers to “place stringent upper limits on the occurrence of binary companions,” according to the paper. But the lack of detection also means they can’t place any constraints or limits on the binary orbital separation or mass ratio distributions of this population.

This survey only examined older, dimmer brown dwarfs. Younger brown dwarfs can still have their binary partners. Studies of younger brown dwarfs show that around eight percent of them have binary partners. In fact, the younger the brown dwarf, the more likely it is to have a binary partner. “These findings marginally confirm the idea that the decrease in binary frequencies with later type observed across the stellar and substellar regimes for the field population might continue throughout the substellar mass range down to the very lowest masses, as illustrated in Fig. 12,” the authors explain.

This is Figure 12 from the study, and it illustrates the rate of brown dwarf binary companions as brown dwarfs age. The binary frequency is shown on the y-axis, and the spectral type, which relates to age, is on the x-axis. Each mark inside the graph plots the results of a study of brown dwarf companions, including this one in pink. The graph clearly shows that younger brown dwarfs have more binary companions than aged brown dwarfs. Image Credit: Fontanive et al. 2024.

In a press release, lead author Fontanive explained why brown dwarfs lose their binary partners over time.

“Our Hubble survey offers direct evidence that these binaries that we observe when they’re young are unlikely to survive to old ages; they’re likely going to get disrupted. When they’re young, they’re part of a molecular cloud, and then, as they age, the cloud disperses. As that happens, things start moving around, and stars pass by each other. Because brown dwarfs are so light, the gravitational hold tying wide binary pairs is very weak, and bypassing stars can easily tear these binaries apart,” said Fontanive.

The authors point out that there’s an inevitable weakness in their results. Since brown dwarfs are so small and dim, the usual methods of detecting companions don’t work. Astronomers rely on the transit method and the radial velocity method to detect companion objects, whether planets orbiting stars or other objects in relationships with one another.

But their inherent dimness makes detecting transits very difficult. Their inherent low masses likewise make the radial velocity ineffective. That leaves them with the direct optical detection method the researchers in this study relied on.

There could be a better way.

Astrometry might provide a more viable alternative approach to search for companions to faint brown dwarfs, although very little work has been carried out on this side, and no systems have been reported this way so far,” the authors write in the conclusion.

When it comes to astrometry, the ESA’s Gaia spacecraft is the standard-bearer. It has the power to detect Jupiter-mass companions when they’re orbiting main sequence stars, but detecting binary brown dwarfs is still difficult, even for Gaia. Gaia has detected many brown dwarfs, but for now, it’s up to direct imaging to detect brown dwarf binary pairs. In this study, direct imaging found no widely separated binary companions despite the HST’s effectiveness.

“With an excellent sensitivity and completeness to companions on wide orbital separations, our survey robustly confirms that wide companions are extremely rare in the Galactic field around the lowest mass systems,” the authors write. Any companions would need to be inside the 1 to 5 AU limit of this work.

“Our results, with no detection of wide companions out of 33 observed objects, reinforce the idea that the widely separated binaries with very low-mass primaries identified in young associations have no counterparts among isolated objects in the Solar neighbourhood,” the authors conclude.

The post Brown Dwarf Pairs Drift Apart in Old Age appeared first on Universe Today.

Categories: Science

Dwarf Galaxies Could be the Key to Explaining Dark Matter

Universe Today Feed - Mon, 03/25/2024 - 12:35pm

If you have a view of the southern celestial sky, on a clear night you might see two clear smudges of light set off a bit from the great arch of the Milky Way. They are the Large and Small Magellanic Clouds, and they are the most visible of the dwarf galaxies. Dwarf galaxies are small galaxies that typically cluster around larger ones. The Milky Way, for example, has nearly two dozen dwarf galaxies. Because of their small size, they can be more significantly affected by dark matter. Their formation may even have been triggered by the distribution of dark matter. So they can be an excellent way to study this mysterious unseen material.

In a recent study, a team looked at dwarf galaxies to see exactly what they would reveal about dark matter. Specifically, they were interested in how dark matter might interact with itself. One idea about dark matter particles is that when they collide with each other they could emit gamma-ray light. This would mean that the central regions of galaxies should show evidence of gamma radiation without a clear astrophysical source. There have been some studies looking for gamma rays within our own galaxy, but the results have been inconclusive.

This new study focused on dwarf galaxies because they are smaller and therefore less likely to obscure gamma-ray light from colliding dark matter. There are also plenty of dwarf galaxies within our local group. Using 14 years of archival data from the Fermi-Large Area Telescope (LAT), the team looked at 50 dwarf galaxies. Overall they didn’t find strong evidence of gamma-ray emissions from any of the galaxies, but in 7 of them they found a small statistical excess at around 2? – 3?. To be definitive we’d like to see it at a level of 5?, so this result is far from conclusive. But if we take the energy levels of the excess at face value, it would put the mass of dark matter particles around 30 – 50 GeV or 150 ? 230 GeV, depending on the way dark matter might decay. By comparison, protons have a mass of about 1 GeV.

So once again a study of dark matter fails to discover the elusive particles. But as with earlier studies, this research narrows down what dark matter might be. Specifically, the study rules out certain mass ranges for dark matter more than ever before. It’s yet another small step toward solving the mystery of dark matter.

Reference: McDaniel, Alex, et al. “Legacy analysis of dark matter annihilation from the Milky Way dwarf spheroidal galaxies with 14 years of Fermi-LAT data.” Physical Review D 109.6 (2024): 063024.

The post Dwarf Galaxies Could be the Key to Explaining Dark Matter appeared first on Universe Today.

Categories: Science

Pushing back the limits of optical imaging by processing trillions of frames per second

Matter and energy from Science Daily Feed - Mon, 03/25/2024 - 10:57am
Pushing for a higher speed isn't just for athletes. Researchers, too, can achieve such feats with their discoveries. A new device called SCARF (for swept-coded aperture real-time femtophotography) can capture transient absorption in a semiconductor and ultrafast demagnetization of a metal alloy. This new method will help push forward the frontiers of knowledge in a wide range of fields, including modern physics, biology, chemistry, materials science, and engineering.
Categories: Science

Pushing back the limits of optical imaging by processing trillions of frames per second

Computers and Math from Science Daily Feed - Mon, 03/25/2024 - 10:57am
Pushing for a higher speed isn't just for athletes. Researchers, too, can achieve such feats with their discoveries. A new device called SCARF (for swept-coded aperture real-time femtophotography) can capture transient absorption in a semiconductor and ultrafast demagnetization of a metal alloy. This new method will help push forward the frontiers of knowledge in a wide range of fields, including modern physics, biology, chemistry, materials science, and engineering.
Categories: Science

Scientists deliver quantum algorithm to develop new materials and chemistry

Matter and energy from Science Daily Feed - Mon, 03/25/2024 - 10:50am
Scientists published the Cascaded Variational Quantum Eigensolver (CVQE) algorithm in a recent article, expected to become a powerful tool to investigate the physical properties in electronic systems.
Categories: Science

Scientists deliver quantum algorithm to develop new materials and chemistry

Computers and Math from Science Daily Feed - Mon, 03/25/2024 - 10:50am
Scientists published the Cascaded Variational Quantum Eigensolver (CVQE) algorithm in a recent article, expected to become a powerful tool to investigate the physical properties in electronic systems.
Categories: Science

An Asteroid Found Sharing the Orbit of Mars

Universe Today Feed - Mon, 03/25/2024 - 10:50am

Astronomers discovered another asteroid sharing Mars’ orbit. These types of asteroids are called trojans, and they orbit in two clumps, one ahead of and one behind the planet. But the origins of the Mars trojans are unclear.

Can this new discovery help explain where they came from?

There are now 14 known Mars Trojans and the name of the newest one is 2023 FW14. They’re in two groups, one 60 degrees ahead and one 60 degrees behind Mars. These are the Lagrange 4 and Lagrange 5 points.

Most of the Mars trojans are at the L5 point, and this newly discovered one is the second one found at the L4 point.

New research published in the journal Astronomy and Astrophysics presents the discovery. Its title is “Dynamics of 2023 FW14, the second L4 Mars trojan, and a physical characterization using the 10.4 m Gran Telescopio Canarias.” The lead author is Raul de la Fuente Marcos from the Earth Physics and Astrophysics Department at the Universidad Complutense de Madrid.

Scientists aren’t certain where the Mars trojans came from. Other trojans like the Jupiter trojans may have been captured by Jupiter in the Solar System’s early years. Or Jupiter may have captured them later when it migrated.

But Mars is a much less massive planet, and astronomers aren’t certain if Mars can capture trojans the same way Jupiter does. The Mars trojans could be as old as the Jupiter trojans, but some evidence suggests otherwise. The dozen or more trojans at the Mars L5 point seem to be a family from the same collision. The family is called Eureka, and their spectra indicate an olivine-rich composition.

Olivine is relatively rare in the main asteroid belt. That’s led some researchers to suggest that the L5 Mars trojans are debris from an ancient impact between Mars, where olivine is common, and a planetesimal.

The two L4 Mars trojans are different. They don’t have the same spectra as the L5 trojans, but the pair do show some similarities in their spectra, so a common origin for these two is a possibility.

In this paper, the researchers set out to determine 2023 FW14’s origins. They used the Gran Telescopio Canarias for their work. It’s a 10.4-meter telescope in Spain’s Canary Islands with an attached instrument called the OSIRIS camera spectrograph.

2023 FW14’s spectrum places it in the same class as an Xc-type asteroid. The X-type name contains several different types of asteroids with similar spectra but probably with different compositions. Xc-types are a sub-class of the X-types that are intermediate between C-type asteroids, the most common type of asteroid in the Solar System, and the uncommon K-type asteroids.

This graph from the research shows the spectrum of 2023 FW14 and several spectra of the other known L4 Mars Trojan (121514) 1999 UJ7. Orange shows 2023 FW14, with the red line representing the best asteroid taxonomical match, the Xc-type. Teal, blue, and green show different published spectra of 1999 UJ7. The gray area fills the entire domain between the mean B-type and D-type classes of asteroids. Image Credit: Marcos et al. 2024.

The researchers also used N-body simulations to try to understand the new asteroid’s resonance with Mars. Trojans follow what are known as tadpole orbits. Tadpole orbits are influenced by Earth’s gravity, which causes objects to librate or accelerate or decelerate alternately.

Tadpole orbits are complex. Asteroids on these orbits exchange large amounts of energy and angular momentum with a planet moving in a circular orbit. Tadpole loops are made of multiple overlapping epicyclic loops.

This video illustrates the tadpole orbit followed by an asteroid in Jupiter’s L4, not Mars’ L4, but the concept is the same.

2023 FW14 has a higher orbital eccentricity and lower inclination than Mars’ other L4 trojan. This means that it occupies an unstable region and orbits at the whim of several different resonances. That instability means that in a few million years, it’ll likely be ejected.

The researchers calculated its size as approximately 318 metres (+493/-199.) That makes it one of the smallest known trojans so far.

As for its origins, the authors say that there are two possibilities.

Its long-term behaviour, including its past, suggests that it was captured from the Near Earth Asteroid (NEA) population of Mars-crossing asteroids. But it could be a fragment of another trojan, as well, one that is so far undiscovered, or one that is no longer a trojan.

Spectral data suggests something else. Both of the L4 asteroids appear to be more primitive than Mars’ L5 trojans. 2023 FW14’s spectrum also supports the idea that it’s a captured Mars-crossing NEA. However, that data isn’t as clear, according to the authors, and can’t be used to rule out the other hypothesis, which is that the asteroid formed in situ. “Although incomplete, the data support the interpretation of 2023 FW14 as an interloper captured from the Mars-crossing NEA population, but they cannot be used to reject the competing hypothesis that 2023 FW14 was produced in situ,” they write.

Whatever its origins are, the researchers calculate that 2023 FW14 has about 10 million years before it’s ejected from its trojan orbit. It’s a temporary trojan, and this discovery could prove that Mars trojans can be temporarily captured, something that so far has been unproven.

The post An Asteroid Found Sharing the Orbit of Mars appeared first on Universe Today.

Categories: Science

No, scientists are not bringing back the woolly mammoth

Why Evolution is True Feed - Mon, 03/25/2024 - 9:45am

If you watch or read the news, you can hardly avoid the newest hype about the “de-extinction” of the woolly mammoth (Mammuthus primigenius)—hype that implies that scientists, using genetic engineering, are on the verge of bringing back that extinct pachyderm. (The species, which coexisted with humans, went extinct about 4,000 years ago, when the Egyptians were still thriving.)

Yes, in a Jurassic-Parkish gambit, scientists are proposing to bring the mammoths back: to “de-extinct” them. A company called Colossal Biosciences, with George Church as its founder, proposes to give us woolly mammoths again, and may even allow us to fill the tundra-steppes of Eurasia with a species that no longer lives there.

It’s not true. They are not producing real woolly mammoths, and the program will not succeed even if they produce the faux mammoths they’re trying to make.

In my previous post on this, called “a mammoth debacle,” I pointed out a number of problems with this effort, not the least the misrepresentation by the media (encouraged, I think, by the scientists) that they really were going to bring back the species that had gone extinct. This is not true—not even close.

What they are going to do is put a handful of mammoth genes (we have the mammoth DNA sequence since we have individuals dug out of the permafrost) into an elephant genome, producing, so the company hopes, a large, hairy elephant with tusks. In other words, the animal they propose to produce is simply an elephant with a few mammoth genes that makes it look superficially like a mammoth. One problem is that we don’t know exactly which genes produce these traits in the mammoth; all we have are DNA sequences. We can investigate what the genes do, but putting them in an elephant genome via CRISPR and hoping that the result will look like a mammoth, is an expensive process, and likely to fail. And you don’t get many chances to fail, because each time you do this you need a female elephant in heat that you can impregnate with a genetically modified elephant egg.

But wait! The problems are much greater than this! Here’s what I wrote last time:

Further, a lot of other genes differ between a mammoth and an Asian elephant. What guarantee is there that the inserted mammoth genes would be expressed correctly, or even work at all in concert with the Asian elephant developmental system?

But it gets worse. Since you can’t implant a transgenic embryo into an elephant mom (we don’t know how to do that, and we would get just one or two chances), Church had this bright idea:

Initially, Dr. Church envisioned implanting embryos into surrogate female elephants. But he eventually soured on the idea. Even if he could figure out in vitro fertilization for elephants — which no one has done before — building a herd would be impractical, since he would need so many surrogates.

Instead, Dr. Church decided to make an artificial mammoth uterus lined with uterine tissue grown from stem cells. “I’m not making a bold prediction this is going to be easy,” he said. “But everything up to this point has been relatively easy. Every tissue we’ve gone after, we’ve been able to get a recipe for.”

An artificial mammoth uterus? Seriously? If you think that’s gonna work, I have some land in Florida I’d like to sell you. Of course, if you’re going to breed these things, you’d have to make two of them of opposite sexes. Could they even do that?

I haven’t even mentioned the ecological problems. Mammoths no doubt had cold-tolerance genes and behavioral genes for existing on the northern tundra-steppes and tending baby mammoths. How are they going to find those genes?

Now the Washington Post tells us (and everybody else) that Colossal Biosciences is “close” to producing this mammoth, which is really a big hairy elephant. But they don’t say that in the headlines. But at least the Post mentions some of the problems with this doomed effort, quoting scientists who are dubious about the venture. And, luckily, those scientists include our own Matthew Cobb.

But the bottom line is: NO, they are not going to bring back the woolly mammoth, nor will they bring the species back as a going concern.

Click below to read, or find the article archived here.

Quotes from the paper are indented. The big news is that the company is now able to get elephant stem cells that they can genetically engineer, making them a bit mammothier. These genetically engineered cells are then to be injected into a female elephant when she is in estrus. The news, as Matthew told me (he’s quoted in the piece), is that “they are able to fiddle around with elephant stem cells for the first time.”  But again, this that just allows production of a big hairy elephant with tusks.

But I digress. From the piece:

A company aiming to bring extinct animals back from the dead said it has taken an elephant-sized step toward genetically resurrecting the woolly mammoth, a wild if contentious goal to repopulate the Arctic tundra with a missing titan

Colossal Biosciences, a biotechnology company based in Dallas, announced Wednesday that it has produced a line of Asian elephant stem cells that can be coaxed to transform into other types of cells needed to reconstruct the extinct giant — or at a least a mammoth-like elephant designed to thrive in the cold.

“It’s probably the most significant thing so far in the project,” said George Church, a Harvard geneticist and Colossal co-founder. “There are many steps in the future.”

For proponents, bringing back vanished animals is a chance to correct humanity’s role in the ongoing extinction crisis. Breakthroughs in their field, they say, may yield benefits for animals still with us, including endangered elephants.

Yet the technical challenges of birthing into the world a living, breathing mammoth remain, well, colossal. And the project raises hairy ethical questions: Who decides what comes back? Where will the reborn species go? Could the money be better spent elsewhere? And how hard will “de-extinction,” as the revival efforts are known, be on the animals themselves?

And the BIG NEWS:

Scientists have produced such stem cells in the lab for other animals, including humans, mice, pigs and even rhinos. But for years, getting the right elephant stem cells to test all those cold-climate characteristics proved elusive, in part because elephant cells’ ability to avoid cancer made reprogramming them difficult.

Colossal said they have produced the stem cells they need by suppressing the anti-cancer genes and bathing the cells in the right chemical cocktail. Colossal published a preprint Wednesday that is not yet peer-reviewed. The company said it is working to place the study in a peer-reviewed scientific journal.

I’m curious how they’re going to test whether a given gene, beyond producing hair, increases cold-tolerance.

Further, Matthew and I are both concerned with the ethical questions, especially bringing into being a mammothy elephant not designed to survive on the tundra, and then putting it in that habitat. It has no mate, it doesn’t have the genes for surviving on the tundra, and it will likely die.  If scientists ever screw up by “playing God,” well, this may be one example.

Here’s Matthew and another biologist expressing doubt about the whole mishigass:

Matthew Cobb, a zoologist at the University of Manchester in England, said all those “ifs” may be insurmountable. There is no guarantee that the modified chromosomes can be introduced to an elephant cell, or if that an embryo will take hold in an elephant womb.

And perhaps more profoundly, there is the question of how a mammoth, if born, will learn to behave like a mammoth. “Most of the mammals and birds that are being talked about have complex social and cultural interactions that have been lost,” Cobb said. “They are not simply their genes.”

Modern elephants, for instance, are highly social beings, passing down knowledge about the location of watering holes and other survival skills from one generation to the next. Their ancient cousins may be similar. “They’ve got no elders to raise them, to teach them,” Browning said. “They’re got no way of learning how to be mammoths.”

And any living surrogate elephant meant to gestate and give birth to a new mammoth will go through some degree of hardship. “How many dead elephants are we willing to have to get one woolly one?” said Tori Herridge, a paleobiologist specializing in ancient elephants at the University of Sheffield in England.

Finally, there’s the artificial uterus problem. Last night the NBC News said a woolly mammoth could be only five years away. Don’t you believe it! Here’s Church touting not only bringing back the mammoth, but trumpeting (pardon the pun) the idea that this complicated technology could help save modern species of elephants (there are three: two species of African elephant and the Asian elephant):

Colossal said its long-term goal is to use artificial wombs to gestate the animals, itself a tall technological task. The company notes that its research into elephant cells can help with current conservation efforts, such as potential treatments for a form of herpes that kills young elephants. Indeed, the company hopes to make money by licensing or selling some of the technologies it creates along the way.

“It’s not so much bringing back the mammoth, it’s saving an endangered species,” Church said. “It’s working out technology that’s useful for conservation and climate change.”

But Cobb said the biggest threats facing elephants are hunting, habitat destruction and other conflicts with humans, adding: “How will a greater understanding of cell biology help?”

Ceiling Cat bless Dr. Cobb for fighting the hype that creeps into science reporting!

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A satirical article that appeared in Clickhole (h/t: RM). Click to read:

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