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On December 27th, 2024, the Chilean station of the Asteroid Terrestrial-impact Last Alert System (ATLAS) detected 2024 YR4. This Near-Earth Asteroid (NEA) belongs to the Apollo group, which orbits the Sun with a period of approximately four years. For most of its orbit, 2024 YR4 orbits far from Earth, but sometimes, it crosses Earth’s orbit. The asteroid was spotted shortly after it made a close approach to Earth on Christmas Day 2024 and is now moving away. Additional observations determined it had a 1% probability of hitting Earth when it makes its next close pass in December 2032.

This led the International Asteroid Warning Network (IAWN) – overseen by the United Nations Office for Outer Space Affairs (UNOOSA) – to issue the first-ever official impact risk notification for 2024 YR4. The possibility of an impact also prompted several major telescopes to gather additional data on the asteroid. This included the Subaru Telescope at the Mauna Kea Observatory in Hawaii, which captured images of the asteroid on February 20th, 2025. Thanks to the updated positional data from these observations, astronomers have refined the asteroid’s orbit and determined that it will not hit Earth.

This is not the first time the odds of the asteroid hitting Earth have been reevaluated. Throughout February, refined measurements of the asteroid altered the estimated likelihood multiple times, first to 2.3% and then to 3.1%, before dropping significantly to 0.28%. Thanks to the observations of the Subaru Telescope, which were conducted at the request of the JAXA Planetary Defense Team and in response to the IAWN’s call for improved orbital tracking, the chance of impact has been downgraded to 0.004%.

Monte Carlo modeling of 2024 YR4’s swath of possible locations as of February 23rd, 2025 – 0.004% probability of impact. Credit: iawn.net

The updated estimate was calculated by NASA’s Center for NEO Studies (CNEOS), the ESA’s Near-Earth Objects Coordination Centre (NEOCC), and the NEO Dynamic Site (NEODyS). The Subaru observations were conducted using the telescope’s Hyper Suprime-Cam (HSC), a wide-field prime-focus camera that captured images of 2024 YR4 as it grew dimmer. The observations have since been forwarded to the Minor Planet Center (MPC) of the International Astronomical Union (IAU). Dr. Tsuyoshi Terai of the National Astronomical Observatory of Japan (NAOJ), who led the observations, explained:

“Although 2024 YR4 appeared relatively bright at the time of its discovery, it has been steadily fading as it moves away from the Earth. By late February, observations would have been extremely challenging without a large telescope. This mission was successfully accomplished thanks to the Subaru Telescope’s powerful light-gathering capability and HSC’s high imaging performance.”

Based on these latest observations, the IAWN reports that 2020 YR4 will “pass at a distance beyond the geosynchronous satellites and possibly beyond the Moon.” They also indicate that there is no significant potential that the asteroid will impact Earth in the next century. The IAWN also states that it will continue to track 2024 YR4 through early April. At this point, it will be too faint to image and won’t be observable from Earth again until 2028.

Further Reading: NAOJ

The post Good News! The Subaru Telescope Confirms that Asteroid 2024 YR4 Will Not Hit Earth. appeared first on Universe Today.

There are several well-documented health risks that come from spending extended periods in microgravity, including muscle atrophy, bone density loss, and changes to organ function and health. In addition, astronauts have reported symptoms of immune dysfunction, including skin rashes and other inflammatory conditions. According to a new study, these issues could be due to the extremely sterile environment inside spacecraft and the International Space Station (ISS). Their results suggest that more microbes could help improve human health in space.

by Greg Mayer

As someone interested in history, I am both interested and wary when analogies are drawn among different periods and events in history, especially applying the past to the present day. And, as another prelude, I should note that I have said here before at WEIT that Bret Stephens is wrong about most things. But when he’s right, he’s right, and he’s right about yesterday’s cringe-inducing display of depravity by the erstwhile leaders of the free world, the President and Vice President of the United States. [JAC: You can find Stephens’s piece archived here.] I found Stephens’ historical analogy to the pre-Pearl Harbor meeting between Franklin D. Roosevelt and Winston Churchill, which led to the Atlantic Charter, whose principles include that there should be “no aggrandizement, territorial or other” and that “sovereign rights and self-government [shall be] restored to those who have been forcibly deprived of them”, very clarifying. Money quote:

If Roosevelt had told Churchill to sue for peace on any terms with Adolf Hitler and to fork over Britain’s coal reserves to the United States in exchange for no American security guarantees, it might have approximated what Trump did to Zelensky.

Interview with Adam Russell; News Items: Congestion Pricing, AI Therapists, Redefining Dyslexia, Small Modular Reactors for Cargo Ships; Who's That Noisy; Science or Fiction

Novel technology intends to redefine the virtual reality experience by expanding to incorporate a new sensory connection: taste.

Physicists provide a viable and testable explanation for how UHECRs are created.

In the race to meet the growing global demand for lithium -- a critical component in batteries for electric vehicles -- a team of researchers has developed a breakthrough lithium extraction method that could reshape the industry. In their study, the researchers demonstrated near-perfect lithium selectivity by repurposing solid-state electrolytes (SSEs) as membrane materials for aqueous lithium extraction. While originally designed for the rapid conduction of lithium ions in solid-state batteries -- where there are no other ions or liquid solvents -- the highly ordered and confined structure of SSEs was found to enable unprecedented separation of both ions and water in aqueous mixtures.

On December 3rd, 2018, NASA’s Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer (OSIRIS-REx) successfully rendezvoused with the Near-Earth Asteroid (NEA) 101955 Bennu. Over the next two years, the mission collected rock and regolith samples from the asteroid’s surface. By September 24th, 2023, the mission’s sample return capsule (SRC) entered Earth’s atmosphere and was collected by NASA scientists. Analysis of these samples is already providing insight into what conditions were like during the early Solar System.

According to a recent study, the known trajectory and timing of the SRC’s return provided a rare opportunity to record geophysical signals produced by the capsule using a new method. Because it was traveling at hypersonic speeds as it flew through the atmosphere, the SRC’s return produced a sonic boom that impacted the ground. Using distributed acoustic sensing (DAS) interrogators and surface-draped fiber-optic cables, the team carried out the first reported recording of an SRC reentry with distributed fiber-optic sensing technology.

The team was led by Dr. Carly M. Donahue and consisted of her colleagues from the Earth and Environmental Sciences Division at the Los Alamos National Laboratory (LANL), as well as the Department of Geosciences at Colorado State University and fiber optic-based distributed sensor developer Silixa LLC. The paper that details their findings, “Detection of a Space Capsule Entering Earth’s Atmosphere with Distributed Acoustic Sensing (DAS),” recently appeared in the journal Seismological Research Letters.

The sample return capsule from the OSIRIS-REx mission is seen shortly after touching down in the Utah desert on September 24th, 2023. Credit: NASA/Keegan Barber

Since the end of the Apollo Era, scientists have studied sample return capsules re-entering Earth’s atmosphere. These studies have helped scientists develop safe and effective methods for sample-return missions and provided insight into the atmospheric entry of meteoroids and asteroids. Until now, these studies employed infrasound and seismic sensors to record the resulting geophysical signals. However, Dr. Donahue and her team saw an opportunity since the trajectory and timing of the OSIRIS-REx mission’s SRC were known in advance.

As Dr. Donahue told Universe Today via email, the reentry was a chance for them to test DAS systems with fiber optic cables to record the geophysical effects produced by the sonic boom. “DAS systems interrogating an optical fiber are still relatively rare,” she said. “Knowing ahead of time the precise trajectory gave us the scarce opportunity to situate multiple DAS interrogators near the point of highest heating and capture the sonic boom as it impacted the ground.”

The team rapidly deployed two DAS interrogators and more than 12 km (7.45 mi) of surface-draped fiber-optic cables. Their network included six collocated seismometer-infrasound sensor pairs, all spread across two sites near the town of Eureka in the Nevada Desert. As Dr. Donahue described:

“Once the team got the hang of rolling out the 4 spools of optical fiber that each weighed over 100 kgs, installing and retrieving the fiber took less time than setting up the six co-located seismic and infrasound stations. Approximately 5 km of the optical fiber was located at the local Eureka airport, along with many other teams deploying sensors such as infrasound, seismic, and GPS.  The other 7 km of fiber was located along a remote dirt road in Newark Valley.”

With the help of this network, the team obtained a stunning profile of the sonic boom as it struck the ground. The DAS interrogators recorded an impulsive arrival with an extended coda that had similar features to those recorded by the seismometers and infrasound sensors. Whereas traditional sensors only measure sonic booms at one point, Dr. Donahue said that her team’s data revealed how the boom’s wavefront transformed as it impacted the irregular terrain of the Nevada landscape.

In addition to being the first time these methods were used to record an SRC reentry, the results of this test could have significant implications when it comes to predicting potential meteor and asteroid strikes. Said Dr. Donahue:

“By having an extremely dense array of sensors, DAS has the possibility of better characterizing the trajectory and size of a meteor. The topology (e.g., hills) of the ground is known to have an influence on wavefront recorded at the surface of the earth. By having a dense line of sensors that span over the changes in the earth’s elevation, these effects could be better accounted for to produce a more accurate characterization of a meteor’s trajectory.”

Following the completion of its primary mission, the OSIRIS-REx, NASA prepped the spacecraft for the next phase of its mission. In 2029, the spacecraft – renamed the OSIRIS-APEX (Apophis Explorer) – will rendezvous with the Near-Earth Asteroid 99942 Apophis and collect another sample.

Further Reading: GeoScienceWorld

The post Detection of a Space Capsule Entering Earth’s Atmosphere with Distributed Acoustic Sensing (DAS) appeared first on Universe Today.

The Andromeda Galaxy, our nearest large neighbour, has 36 identified dwarf galaxies. The Hubble telescope took images of Andromeda and its dwarfs during more than 1,000 orbits, creating a precise 3D map. Astronomers used these observations to reconstruct the dwarf galaxies’ star formation histories.

The results show that their environment plays a critical role in their star formation and their quenching.

When galaxies are quenched, they no longer form stars. It happens because the supply of star-forming gas is diminished or somehow made unavailable. This typically happens because of black hole feedback or when a galaxy moves through a dense galaxy cluster, and its gas is stripped away.

However, the dwarf galaxies around Andromeda (M31) seem to follow an unusual pattern of star formation and quenching. New research shows that the rambunctious environment around M31 is responsible.

The research is “The Hubble Space Telescope Survey of M31 Satellite Galaxies. IV. Survey Overview and Lifetime Star Formation Histories,” published in The Astrophysical Journal. Alessandro Savino from the Department of Astronomy at UC Berkeley is the lead author.

Astronomers aren’t certain how many dwarf galaxies the Milky Way has, but it looks like Andromeda, with its dozens of dwarf galaxies, has had a more active history of mergers and absorptions. M 31 may have merged with another massive galaxy a few billion years ago, and its abundant dwarf galaxies could be from its eventful past and its sheer mass.

“Our knowledge of low-mass galaxy formation has long been anchored by Milky Way (MW) satellite galaxies,” the authors write. “It remains unclear if the insights learned from MW satellites, and their particular formation pathways, are applicable to other satellite systems and low-mass galaxies in general.”

“There’s always been concerns about whether what we are learning in the Milky Way applies more broadly to other galaxies.”

Daniel Weisz, UC Berkeley.

Studying dwarf galaxies is challenging. We’re inside the Milky Way, which makes observing its outskirts difficult. Dwarf galaxies are also dim, adding to their detection difficulty. Detecting them in distant galaxies is likewise difficult. Comparing the MW low-mass dwarf galaxies with those in other galaxies means contending with multiple layers of difficulty. Fortunately, the Andromeda galaxy is wide open to observations.

This large photomosaic of Andromeda is from the Hubble. It’s the largest one ever assembled from NASA/ESA Hubble Space Telescope observations. Click on the image to access the full-size version. Image Credit: NASA, ESA, B. Williams (University of Washington)

“From >1000 orbits of HST imaging, we present deep homogeneous resolved star colour-magnitude diagrams that reach the oldest main-sequence turnoff and uniformly measured star formation histories (SFHs) of 36 dwarf galaxies associated with the M31 halo,” the authors write. They did the same for 10 additional fields in M31, M33, and the Giant Stellar Stream. M33 is the Triangulum Galaxy, the third largest member of the Local Group after M31 and the Milky Way. M33 is also one of M31’s satellites. The Giant Stellar Stream is a long ribbon of stars that are the remnants of a galaxy absorbed by M31.

For context, this image shows some of the main features around Andromeda, including the Giant Stellar Stream, M32, and NGC 205, another of Andromeda’s dwarf galaxies. Image Credit: Ferguson et al. 2000

The observations reveal a tight correlation between a dwarf’s star formation history, its mass, and its proximity to M31.

“We see that the duration for which the satellites can continue forming new stars really depends on how massive they are and on how close they are to the Andromeda galaxy,” said lead author Savino in a press release. “It is a clear indication of how small-galaxy growth is disturbed by the influence of a massive galaxy like Andromeda.”

Astronomers are in a difficult spot when it comes to studying galaxies in detail. Our own Milky Way is the only galaxy that’s open to detailed investigation. The temptation is to draw parallels between our knowledge of the MW and other galaxies.

“There’s always a tendency to use what we understand in our own galaxy to extrapolate more generally to the other galaxies in the universe,” said principal investigator Daniel Weisz of the University of California at Berkeley. “There’s always been concerns about whether what we are learning in the Milky Way applies more broadly to other galaxies. Or is there more diversity among external galaxies? Do they have similar properties? Our work has shown that low-mass galaxies in other ecosystems have followed different evolutionary paths than what we know from the Milky Way satellite galaxies.”

These detailed, 1,000-orbit observations of Andromeda are helping change this. They reveal a more chaotic environment than in the Milky Way.

“Everything scattered in the Andromeda system is very asymmetric and perturbed. It does appear that something significant happened not too long ago,” said Weisz.

One of the research’s surprising findings is that about half of M31’s dwarf galaxies lie along the same plane, called the Great Plane of Andromeda, and are moving in the same direction. “That’s weird. It was actually a total surprise to find the satellites in that configuration, and we still don’t fully understand why they appear that way,” said Weisz.

The galaxies along this plane don’t appear to be any different from those on the plane. “There is no difference between the median SFH (star formation history) of galaxies on and off the great plane of Andromeda satellites,” the authors write.

The researchers used colour-magnitude diagrams (CMDs), an important tool in astronomy, to learn more about the star formation history in Andromeda’s dwarf galaxies. CMDs plot a star’s magnitude, or brightness, with its colour. From these plots, astronomers can learn about the age of a stellar population and when star formation was quenched.

The CMDs showed that star formation in dwarf galaxies lasts much longer than expected. It started early and continued, albeit more slowly, by drawing from a reservoir of gas. These results are in sharp disagreement with simulations like TNG 50.

“Star formation really continued to much later times, which is not at all what you would expect for these dwarf galaxies,” said Savino. “This doesn’t appear in computer simulations. No one knows what to make of that so far.”

This figure from the team’s research shows the star formation history (SFH) in Andromeda’s halo, the Giant Stellar Stream, and M33. The red region represents the Epoch of Reionization, the black line shows the best-fit SFH and the grey shows systematic uncertainties. It shows that star formation started early and continued for a long time, albeit at a much slower rate. Image Credit: Savino et al. 2025.

The research also shows that the SFH is no different between dwarf galaxies on the Great Plane of Andromeda and those off of it.

This figure from the study shows the median SFH for the GPoA candidate members (blue line, left panel) and out-of-plane candidates (orange line, middle panel). The gray lines show the SFH of individual galaxies. The right panel shows a direct comparison between the median SFH of the two samples. Image Credit: Savino et al. 2025.

The SFH results in Andromeda are not what we see in the MW. This suggests that the environmental histories, tidal forces, and gas stripping experienced by M31 satellites are different than those around the Milky Way, leading to different star formation patterns over cosmic time. This could be the most significant finding and further exemplifies the risk of extrapolating our knowledge of the Milky Way to other galaxies.

“The results of this study represent a significant step forward in our understanding of the M31 satellite system,” the authors write in their conclusion. They point out that the SFHs they’ve developed will only be more valuable when combined with large data sets acquired in the future. Data sets of the spectral abundance of stars and their proper motions in M31 are being acquired, and some already exist.

Maybe they’ll be able to explain Andromeda’s dwarf galaxies’ unusual properties.

“We do find that there is a lot of diversity that needs to be explained in the Andromeda satellite system,” added Weisz. “The way things come together matters a lot in understanding this galaxy’s history.”

• Press Release:

The post Andromeda’s Dwarf Galaxies Reveal Unique Star Formation Histories appeared first on Universe Today.

When the US Federal Emergency Management Agency removed a map of future climate hazards from its website, researchers built their own version

Rogue planetary-mass objects, also known as free-floating planets (FFPs) drift through space alone, unbound to any other objects. They’re loosely defined as bodies with masses between stars and planets. There could be billions, even trillions of them, in the Milky Way.

Their origins are unclear, but new research says they’re born in young star clusters.

Some free-floating planets (FFPs) form the same way stars form by collapsing inside a cloud. The International Astronomical Union calls them sub-brown dwarfs. But that can’t account for all FFPs, or isolated planetary-mass objects (iPMOs) as they’re sometimes called.

New research in Science Advances shows how FFPs form in young star clusters where circumstellar disks interact with one another.

“This discovery partly reshapes how we view cosmic diversity.”

Lucio Mayer, University of Zurich

The research is titled “Formation of free-floating planetary mass objects via circumstellar disk encounters.” Zhihau Fu from the Department of Physics at the University of Hong Kong and the Shanghai Astronomical Observatory is the lead author, and Lucio Mayer from the University of Zurich is the corresponding author.

“PMOs don’t fit neatly into existing categories of stars or planets,” said corresponding author Meyer. “Our simulations show they are probably formed by a completely different process.”

Astronomers found some of the first evidence of PMOs in the Trapezium Cluster in the year 2,000. The Trapezium is a tight, open cluster of stars in Orion. It’s also relatively young, and half of its stars show dwindling circumstellar disks, a sign that planet formation is taking place. In the research published in 2,000, the authors wrote that “Approximately 13 planetary-mass objects are detected.”

This Hubble Space Telescope image shows the Orion Nebula with the three stars of Orion’s belt prominent. The Trapezium cluster is the bright clump of stars above and to the right of the belt. Most of Trapezium’s stars are obscured by dust. In 2,000, astronomers first found evidence of rogue planets in the Trapezium Cluster. Image Credit: By NASA, ESA, M. Robberto (Space Telescope Science Institute/ESA) and the Hubble Space Telescope Orion Treasury Project Team – http://hubblesite.org/newscenter/newsdesk/archive/releases/2006/01/https://www.spacetelescope.org/news/heic0601/, Public Domain, https://commons.wikimedia.org/w/index.php?curid=1164360

Since then, astronomers have found many more PMOs and hundreds more candidates. Scientists have wondered about their origins, but so far, there are no widely accepted explanations.

“The origin of planetary mass objects (PMOs) wandering in young star clusters remains enigmatic, especially when they come in pairs,” the authors write in their new research. “They could represent the lowest-mass object formed via molecular cloud collapse or high-mass planets ejected from their host stars. However, neither theory fully accounts for their abundance and multiplicity.”

The researchers used hydrodynamic simulations to test another origin for PMOs and found that they have a unique origin story. Instead of forming in a collapsing cloud like stars or in a protoplanetary disk around a young star, they form in the dense environments in young star clusters. The densely packed environments provide another pathway for PMO formation.

In their simulations, the researchers recreated some of the conditions inside young star clusters where stars readily interact with one another. During close encounters between two stars, their circumstellar disks interact. They get stretched into a tidal bridge between the pair of stars, and the gas in the bridge is also compressed into a greater density.

In the simulations, these bridges collapse into filaments, and those filaments collapse even further into dense cores. Eventually, these cores form PMOs of about 10 Jupiter masses. This fruitful process produces many pairs and triplets of PMOs. Astronomers observe a high number of PMO binaries in some clusters, so these simulations appear to match observations.

“Many young circumstellar disks are prone to instabilities due to the self-gravity of disk gas, potentially leading to disk fragmentation and the formation of gaseous planets,” the authors explain in their paper. “Circumstellar disks appear even more unstable when perturbed by a stellar or circumstellar disk flyby.”

This figure from the research shows some of the simulation results. The top panel shows a pair of young stars with interacting circumstellar disks. Two dense cores are forming in the interaction. The bottom panel shows four snapshots from the simulation at different elapsed times. The binary PMOs form in the dense filaments generated in the stellar encounter. Image Credit: Fu et al. 2025.

Even stable and isolated disks can form PMOs during flybys. However, the formation of PMOs is dependent on the combined velocity of the interactions. “For high- and low-velocity encounters, the tidal bridge is either stretched too thin or torn apart by the stars, and thus, forming isolated cores becomes impossible,” the authors explain. The interaction velocity has to be in the middle range.

Some of their simulations also showed up to four PMO cores forming in the filaments. “The middle part of the tidal bridge contracts into thin filaments with line mass over the critical value for stability, forming up to four cores in one encounter,” the researchers write. They explain that the exact number of cores is determined by the length of the filaments and is “sensitive to random density fluctuations.” These fluctuations are very difficult to predict from the encounter parameters.

The PMOs display some particular characteristics. They’re likely to have their own disks, and they’re likely to be metal-poor because of where they get their dust from. “In addition, PMOs and their hosts are expected to be metal-poor since they inherit materials in the parent disks’ outskirts that are susceptible to dust drift and, thus, are metal-depleted,” the authors explain.

The authors calculate that in just one million years, which is the approximate age of the Trapezium Cluster, each star will experience 3.6 encounters with other stars. “The highly efficient PMO production channel via encounters can, therefore, explain the hundreds of PMO candidates (540 over 3500 stars) observed in the Trapezium cluster,” the authors write.

It’s important to note that the results only apply to dense clusters that force interactions between circumstellar disks. “This process can be highly productive in dense clusters like Trapezium forming metal-poor PMOs with disks. Free-floating multiple PMOs also naturally emerge when neighbouring PMOs are caught by their mutual gravity,” the authors write.

“This discovery partly reshapes how we view cosmic diversity,” said co-author Lucio Mayer. “PMOs may represent a third class of objects, born not from the raw material of star forming clouds or via planet-building processes, but rather from the gravitational chaos of disk collisions.”

PMOs can be difficult to spot, so their population is based on preliminary estimates and understandings. But they’re out there, and we’ll only get better at identifying them.

This artist’s impression shows an example of a rogue planet with the Rho Ophiuchi cloud complex visible in the background. Rogue planets have masses comparable to those of the planets in our Solar System but do not orbit a star, instead roaming freely on their own. Image Credit: ESO/M. Kornmesser/S. Guisard

The Upper Scorpius Association contains the next highest-known population of PMOs. A 2021 study identified between 70 and 170 candidate PMOs in the region.

The soon-to-see-first-light Vera Rubin Observator (VRO) will significantly grow the number of known PMOs. More data is better data, and the VRO’s observations will lead to a better understanding of how they form.

“Future studies of various young clusters can further constrain the population of PMOs,” the authors conclude.

• Press Release: Young Star Clusters Give Birth to Rogue Planetary-Mass Objects
• New Research: Formation of free-floating planetary mass objects via circumstellar disk encounters

The post Rogue Planets are Born in Young Star Clusters appeared first on Universe Today.

I got no news today, so I’ll put up some music. This happens one of my favorite jazz solos, and I don’t think I’ve posted it before but came across it on YouTube. It’s a smoking trumpet piece played by Roy Eldridge (1911-1989), nicknamed “Little Jazz” because of his stature. Here he plays with the Gene Krupa Orchestra, and later he played with Artie Shaw’s band.  Unable to form his own big band, Eldredge later confined himself, like Charlie Parker, to small groups.

This rendition of “Rockin’ Chair” is smoking, one of the best trumpet pieces I know. Wikipedia singles it out:

One of Eldridge’s best known recorded solos is on a rendition of Hoagy Carmichael‘s tune, “Rockin’ Chair”, arranged by Benny Carter as something like a concerto for Eldridge. Jazz historian Gunther Schuller referred to Eldridge’s solo on “Rockin’ Chair” as “a strong and at times tremendously moving performance”, although he disapproved of the “opening and closing cadenzas, the latter unforgivably aping the corniest of operatic cadenza traditions.” Critic and author Dave Oliphant describes Eldridge’s unique tone on “Rockin’ Chair” as “a raspy, buzzy tone, which enormously heightens his playing’s intensity, emotionally and dynamically” and writes that it “was also meant to hurt a little, to be disturbing, to express unfathomable stress.”

If you want to hear a very different (but also good) rendition, go here to hear a duo with Louis Armstrong and trombonist Jack Teagarden. This one has vocals.

Virtual reality could get more realistic thanks to scientists inventing an artificial tongue that can taste flavours, such as sourness and umami

A multi-institutional research team has engineered a way to preserve the electrical properties of materials as they are shrunk to the nanoscale. The use of the soft substrate hexagonal boron nitride reduces damage to the atomic structure caused by strain, allowing materials to keep their conductive properties as films as thin as 12 nm.

The effects of Climate Change on Earth’s living systems have led to a shift in biological studies, with attention now being focused on the boundaries within which life can survive. Studying life forms that can thrive in extreme environments (extremophiles) is also fundamental to predicting if humans can live and work in space for extended periods. Last, but not least, these studies help inform astrobiological studies, allowing scientists to predict where (and in what form) life could exist in the Universe.

In a recent study, a team of Italian researchers used brine shrimp (Artemia franciscana) in the earliest stage of development (nauplii) and subjected them to Mars-like pressure conditions. Their results indicate that while the nauplii experienced physiological changes, their development remained largely unchanged. This not only demonstrates that extremophiles show great adaptability and can survive in Mars-like conditions. It also indicates that similar life forms could be found elsewhere in the Universe, representing new opportunities for astrobiological research.

Maria Teresa Muscari Tomajoli, an Astrobiology PhD Candidate at the Parthenope University of Naples, led the study. She was joined by Paola Di Donato, a Professor of Organic and Biological Chemistry at Parthenope. They were joined by researchers from the Federico II University, the INAF-Institute of Space Astrophysics and Planetology (INAF-ISAP), the INAF-Osservatorio Astronomico di Capodimonte, and the Italian Institute for Nuclear Physics (INFN). The paper that details their findings was part of a special volume titled Comparative Biochemistry and Physiology A: Molecular & Integrative Physiology.

Brine Shrimp Artemia franciscana. Credit: Wikipedia

On Earth, extremophiles belong to all three domains of life (Archaea, Bacteria, and Eukarya). They are characterized by their ability to withstand pressure, acidity, temperatures, and other conditions that would be fatal to other organisms. After Earth, Mars is considered the most habitable planet after Earth in the Solar System, hence why most of humanity’s astrobiology efforts are focused there. In addition to the low atmospheric pressure (1/100th of Earth’s at sea level), the surface is subject to extreme temperature variations and is contaminated by perchlorites and toxic metals.

Scientists speculate that if life exists on Mars today, it will likely take the form of microbes living in high-salinity briny patches beneath the surface. As Tomajoli told Universe Today via email, this makes extremophiles (like Artemia franciscana) ideal test subjects for predicting what life is like in similar planetary environments:

“The definition of life is crucial, especially when searching for traces of it on other planetary bodies (e.g., Mars), where life might not exist as we traditionally imagine it. Artemia cysts present an interesting case: in their dormant state, they cannot be classified as living but rather as potential life. Studying organisms with such characteristics helps broaden the perspective in astrobiological research.”

In particular, extremophiles present opportunities for researching species adaptation, which has become a major focus of scientific research due to anthropogenic Climate Change. Worldwide, rising carbon emissions and increasing temperatures are leading to changes in weather patterns, increased ocean acidity, drought, wildfires, and the loss of habitats. As a result, countless marine and terrestrial species are forced to adapt to conditions that are becoming more extreme.

In this April 30, 2021, file image taken by the Mars Perseverance rover and made available by NASA, the Mars Ingenuity helicopter, right, flies over the surface of the planet. Credit: NASA/JPL-Caltech/ASU/MSSS

“In the context of climate change, life conditions are shifting toward extreme boundaries, making survival more challenging for many organisms,” Tomajoli added. “Extremophiles, which thrive in Earth’s most remote environments, are valuable models for understanding metabolic adaptations. Their apparent simplicity is, in fact, an advantage, allowing them to adapt better than more complex organisms to extreme environmental constraints.”

Tomajoli and her colleagues chose Artemia franciscana for their study, a species of brine shrimp known to thrive in high-salinity environments. The eggs they produce, known as cysts, are dormant and can be stored indefinitely, making them extremely useful for aquaculture and scientific research. As Tomajoli indicated, they have also been used in previous space missions, including the Biostack experiment on the Apollo 16 and 17 missions and the ESA’s EXPOSE platform mounted on the International Space Station’s (ISS) exterior.

These experiments all tested the resilience of certain life forms and their progeny to cosmic rays. However, as Tomajoli added, no further studies have been conducted regarding the physiological adaptations of Artemia franciscana, and there is currently no scientific literature available on the topic:

“In particular, Artemia brine shrimps are considered halophiles (literally “salt-loving” organisms) and thrive in environments that can be considered Mars analogs (or laboratories for Mars studies) such as temporary lakes that undergo frequent evaporation, prompting Artemia to produce cryptobiotic cysts. Additionally, Artemia is an easily cultivable model, making it suitable for biological and astrobiological experiments. A recent article by Kayatsha et al., 2024  also showed that Artemia franciscana was among all the microinvertebrates that were tested, the more resistant one to perchlorates salts present in the regolith of simulated martian soil.”

Artist’s impression of water under the Martian surface. Credit: ESA

For their experiment, Tomajoli and her colleagues placed dormant cysts in Mars-like pressure conditions. Once they hatched into nauplii, the team analyzed their aerobic and anaerobic metabolism, mitochondrial function, and oxidative stress. As indicated in their paper, brine shrimp born in Martian pressure conditions managed to adapt quite well. They further share how these results could lead to further studies to evaluate the metabolic adaptations of the cysts to longer exposure times, combinations of different Mars-like conditions, or studies of the adaptations of the nauplii in other stages of development:

“Artemia franciscana showed an exciting potential for physiological adaptations, enabling organisms to cope with the environmental challenges they encounter in space… Nauplii’s cells appear to activate responses to avoid mitochondrial dysfunction and continue their growth processes. These adaptation mechanisms highlight Artemia franciscana’s resilience and ability to thrive in hostile environmental conditions. The results reported in this study further support the potential use of Artemia franciscana for astrobiological purposes, highlighting the animals’ metabolic and redox state changes as a response to adaptation to an extreme condition mimicking the space.”

The implications of this research are far-reaching, embracing astrobiology, human space exploration, and mitigating the effects of Climate Change. Not only could it help point the way toward potential life on Mars, in the interior oceans of icy bodies, and other extreme environments. It could also inform future missions to Mars and other deep-space destinations, where astronauts will need to rely on closed-loop bioregenerative life support systems (BLSS), grow their own food, and conduct research into the effects of exposure to lower gravity, elevated radiation, and other harsh conditions.

At home, the study of extremophiles and adaptation mechanisms could provide insight into climate resilience and adaptation, consistent with the goals outlined in the Sixth Assessment Report (AR6) by the Intergovernmental Panel on Climate Change (IPCC). As they summarize in their paper:

“Understanding the mechanisms of Artemia franciscana adaptations to space-simulated conditions could provide new insights into the study of the limits of life, as well as contribute to the search for biosignatures—traces of past life on other planetary bodies. Additionally, it could offer a viable solution for the long-term survival of human space missions, helping establish self-sustaining populations in confined environments. Artemia could serve as a renewable food source for astronauts, given its richness in essential nutrients, including proteins, lipids, and vitamins.”

Tomajoli and her colleagues have also conducted simulations with a full Mars-like atmosphere for longer periods of time. The paper describing this experiment will be released soon. In the meantime, the search for life on Mars and beyond continues. Knowing it can exist out there and under what conditions will help narrow that search and encourage us to keep investigating.

Further Reading: Science Direct

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Some researchers think OpenAI's giant and expensive latest model is a sign that tech companies cannot keep making progress by continually scaling up

Our Milky Way Galaxy is rich in dark matter. The problem is, we can’t see where it’s distributed because, well, it’s dark. We also don’t completely understand how it’s distributed—in clumps or what? A team at the University of Alabama-Huntsville has figured out a way to use solitary pulsars to map this stuff and unveil its effect on the galaxy.

A technique developed by Dr. Sukanya Chakrabarti and her team is based on some unique characteristics of pulsars. In addition, it uses the presence of a strange wobble of our galaxy. It seems to be induced by interactions with dwarf galaxies such as the Large Magellanic Cloud. That wobble has a connection to the amount of dark matter in the galaxy, and it turns out that pulsars can help map it.

Dark Matter Mapping and Pulsars

Pulsars are the corpses of massive stars. After they explode as supernovae, what remains is a rapidly spinning compressed stellar core. These beasts sport incredibly strong magnetic fields. Those fields twist and coil up as they spin many times per second and send high-speed particles out to space. That causes the pulsar to lose energy. Combined with friction produced by the motions of the twisted magnetic field, the pulsar slows down ever so slightly in a process called “magnetic braking”. Scientists have worked for years to model this process to understand the behavior of pulsars.

Illustration of a pulsar with powerful magnetic fields. They funnel particles to space, and their twisting characteristics help to slow down a pulsar’s spin. That spin is accelerated by the effect of dark matter distribution. Credit: NASA’s Goddard Flight Center/Walt Feimer

The Milky Way Galaxy’s behavior is another part of the dark matter mapping puzzle. Astronomers know it has a substantial component of dark matter that appears not to be evenly spread out. The actual distribution of that mass of dark matter leads to some interesting effects, according to Chakrabarti. “In my earlier work, I used computer simulations to show that since the Milky Way interacts with dwarf galaxies, stars in the Milky Way feel a very different tug from gravity if they’re below the disk or above the disk,” she said. “The Large Magellanic Cloud (LMC)–a biggish dwarf galaxy–orbits our own galaxy, and when it passes near the Milky Way, it can pull some of the mass in the galactic disk towards it–leading to a lopsided galaxy with more mass on one side, so it feels the gravity more strongly on one side.”

Gaia showed our galaxy’s disk, the dark brown horizontal spanning from one side to the other, has a wave. Gaia also showed that the Milky Way has more than two spiral arms. They aren’t as pronounced as we thought. The galaxy’s distribution of dark matter contributes to the shape. Image Credit: ESA/Gaia/DPAC, Stefan Payne-Wardenaar CC BY-SA 3.0 IGO

Chakrabarti compared this interesting galaxy “wobble” to the way a toddler walks–not entirely balanced yet. That wobble affects stars, including pulsars. And it turns out that the different tugs of gravity caused by the distribution of dark matter affects their spindown rates. “So this asymmetry or disproportionate effect in the pulsar accelerations that arises from the pull of the LMC is something that we were expecting to see,” said Chakrabarti. In other words, those tugs of gravity by dark matter give away its distribution and possibly its density throughout the Galaxy.

Building on Previous Work

Chakrabarti and her team previously pioneered the use of binary pulsars to map dark matter in the Galaxy. It turns out that magnetic braking doesn’t affect the orbits of pulsars in binary systems. That makes them useful to measure the amount and distribution of dark matter in the Milky Way. So, the team measured the acceleration of pulsar spin rates due to the effect of the Milky Way’s gravitational potential. That work showed it’s possible to map the galaxy’s gravitational field with data points from more binary pulsars. That includes clumps of galactic dark matter. However, there’s a problem. There are a lot of singular pulsars. There had to be a way to use them, too. And that brings us back to the team’s modeling of pulsar spindown.

Artist’s impression of a binary pulsar by Michael Kramer, Jodrell Bank Observatory. Binaries help map dark matter’s effect on the gravitational field of the galaxy.

“Because of this spindown, we were initially–in 2021 and in our follow-up 2024 paper–forced to use only pulsars in binary systems to calculate accelerations because the orbits aren’t affected by magnetic braking,” said team member Tom Donlon. “With our new technique, we are able to estimate the amount of magnetic braking with high accuracy, which allows us to also use individual pulsars to obtain accelerations.”

Need More Data

Adding more “point source” measurements with single pulsars, Chakrabarti’s team predicts that it should eventually be possible to determine a much more accurate understanding of the distribution of dark matter in the Milky Way. “In essence, these new techniques now enable measurements of very small accelerations that arise from the pull of dark matter in the galaxy,” Chakrabarti said. “In the astronomy community, we have been able to measure the large accelerations produced by black holes around visible stars and stars near the galactic center for some time now. We can now move beyond the measurement of large accelerations to measurements of tiny accelerations at the level of about 10 cm/s/decade. 10 cm/s is the speed of a crawling baby.”

For More Information

UAH Breakthrough Enables the Measurement of Local Dark Matter Density Using Direct Acceleration Measurements for the First Time
Empirical Modeling of Magnetic Braking in Millisecond Pulsars to Measure the Local Dark Matter Density and Effects of Orbiting Satellite Galaxies
Galactic Structure From Binary Pulsar Accelerations: Beyond Smooth Models

The post A New Way to Measure Where the Milky Way’s Dark Matter Is appeared first on Universe Today.

Neutrinos generated through solar fusion reactions travel effortlessly through the Sun’s dense core. Each specific fusion process creates neutrinos with distinctive signatures, potentially providing a method to examine the Sun’s internal structure. Multiple neutrino detection observatories on Earth are now capturing these solar particles, which can be analysed alongside reactor-produced neutrinos with the data eventually enabling researchers to construct a detailed map of the interior of the Sun.

The Sun is a massive sphere of hot plasma at the centre of our solar system and provides the light and heat to make life on Earth possible. Composed mostly of hydrogen and helium, it generates energy through nuclear fusion, converting hydrogen into helium in its core. This process releases an enormous amount of energy which we perceive as heat and light. The Sun’s surface, or photosphere, is around 5,500°C, while its core reaches over 15 million°C. It influences everything from our climate to space weather, sending out solar wind and occasional bursts of radiation known as solar flares. As an average middle-aged star, the Sun is about 4.6 billion years old and will (hopefully) continue burning for another 5 billion years before evolving into a red giant and eventually becoming a white dwarf.

This image shows our Sun during a period of high activity.

The standard solar model (SSM) is used to understand and predict the Sun’s internal structure and evolution, it’s how we work out what’s going on inside the Sun. It explains how, in the Sun’s core, different nuclear fusion reactions are constantly pumping out neutrinos – tiny, nearly massless particles that travel through almost anything. Each type of reaction creates neutrinos with their own properties. These neutrinos may help us to understand more about the interior of the Sun. Right now, we only know about its internal density structure from theoretical models based on the SSM, matched with what we can see on the Sun’s surface. The neutrinos may hold the information that will gives us more direct data about the solar interior. 

Chinese researchers are working on a new neutrino observatory called TRIDENT. They built an underwater simulator to develop their plan. Image Credit: TRIDENT

In a paper published by Peter B. Denton from the Brookhaven National Laboratory and Charles Gourley from Rensselaer Polytechnic Institute they show how solar neutrinos can help us to look inside the Sun and establish its density structure. In contrast, photons of light only tell us about the surface of the Sun as it is right now, and give us a little information about the Sun’s interior hundreds of thousands of years ago. This delay in photons exiting the Sun is because they bounce around the dense solar interior for centuries before escaping. Neutrinos on the other hand give us up to the minute information because they can zip straight through the Sun without getting stopped. 

It has long since been known that neutrinos change their flavour or type (electron neutrino, muon neutrino or tau neutrino) as they travel through matter and that depends on the local density. This is well documented as the Mikheyev-Smirnov-Wolfenstein effect and, by measuring the flux of the neutrino as observed at Earth, compared to unoscillating  predicted flux, the density where the neutrinos were produced can be calculated. Input is also required from independent measurements from neutrino oscillations  that have been created inside nuclear reactors. 

The team demonstrate that the approach does have its limitations  and that there are constraints on just how much density information can be gleaned from the SSM alone. Further data from projects like JUNO and DUNE are needed to further improve the solar internal density profile and give us a more realistic view of the internal workings of our local star.

Source : Determining the Density of the Sun with Neutrinos

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Innovation is a history of someone trying to build a better mouse trap – or at least that’s how it’s described in business school. But what happens if someone tries to build a better version of something that isn’t even commonly used yet? Maybe we will soon find out, as NASA recently supported an effort to build a better type of solar sail as part of its Institute for Advanced Concepts (NIAC) program.

The project, called “The Ribbon” on its announcement page, is a novel take on a typical solar sail and is being developed by a company called TestGuild Engineering out of Boulder, which seems to be run by a sole proprietor known as Gyula Greschik, who also appears to be a researcher at UC Boulder. The Ribbon consists of a “film strip with a diffractive grating” that uses the same principle as a traditional solar sail to move – light pressure. 

The diffractive grating is the key here – when the Ribbon is oriented towards the light from the Sun, the light effectively “pushes” it, just like a solar sail. But, in this case, the diffractive grating causes the force to be directed toward the “leading end” of the Ribbon. Importantly, it does this with no structure components at all – just the Ribbon itself.

Fraser discusses how awesome solar sails are.

If a payload is attached to the other end, eventually, the force being applied to the front will drag the back along with it. It might not happen immediately, but like an actual ribbon, eventually, the force will be transferred down to the payload. That would allow it to effectively tow the payload, much like a traditional solar sail.

This does have some unique advantages, including its ease of storability and potentially infinite scaling—longer ribbons would simply mean more force, much like a larger solar sail would also mean more force. In theory, at least, there is no limit to the scaling of how large you could make the Ribbon, though practically, eventually, you would hit the physical limits of the material you chose to make it out of.

TestGuild has some experience developing projects for NASA already. Back in 2017, it was given a Small Business Innovation Research grant to work on a type of deployable communications array that uses similar structural engineering techniques to the Ribbon. It’s unclear whether that project is still ongoing, but given the new interest from NASA on a completely separate use case with the same PI, it likely isn’t.

Fraser discusses the basic concept behind solar sails.

 Comparing the Ribbon’s use cases to those of more traditional solar sails will take a long time. NIAC Phase I typically takes about a year. In the press release announcing the project, Dr Greschik notes that most of this round will be focused on simulation and feasibility studies. Special emphasis is placed on how the Ribbon responds to small perturbations and what control system would be necessary to stabilize it. So, it may be some time before we see a giant Ribbon pulling a payload through space. However, new solar sail concepts always pop up, and this one could provide some inspiration for the next generation of designs, or it could see itself manifested one day.

Learn More:
Greschik & NASA – The Ribbon
UT – NASA’s Putting its Solar Sail Through its Paces
UT – Project Helianthus – a Solar Sail Driven Geomagnetic Storm Tracker
UT – Solar Sails Could Reach Mars in Just 26 Days

Lead Image:
Artist’s concept of the Ribbon.
Credit – NASA / Gyula Greschik

The post A Giant Ribbon Can Pull Payloads Along appeared first on Universe Today.

Scientists have come up with a lithium ion capacitor using electrodes produced from wood particles that are discarded as waste in sawmills. This biomass is both readily available and sustainable, inexpensive processes have been used to produce electrodes. The results reveal that the materials derived from biomass have excellent properties for obtaining eco friendly, cost-effective systems designed to store high-power energy.