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Ask almost any physicist what the most frustrating problem is in modern-day physics, and they will likely say the discrepancy between general relativity and quantum mechanics. That discrepancy has been a thorn in the side of the physics community for decades. While there has been some progress on potential theories that could rectify the two, there has been scant experimental evidence to support those theories. That is where a new NASA Institute for Advanced Concepts grantee comes in - Selim Shahriar from Northwestern University, Evanston, was recently funded to work on a concept called the Space-borne Ultra-Precise Measurement of the Equivalent Principle Signature of Quantum Gravity (SUPREME-GQ), which he hopes will help collect some accurate experimental data on the subject once and for all.

Let’s face it: Space is a hostile environment for humans. Even on Mars, settlers might have a hard time coping with potentially lethal levels of radiation, scarce resources and reduced gravity. In “Mickey 17” — a new sci-fi movie from Bong Joon Ho, the South Korean filmmaker who made his mark with “Parasite” — an expendable space traveler named Mickey (Robert Pattinson) is exposed over and over again to deadly risks. And every time he’s killed, the lab’s 3D printer just churns out another copy of Mickey.

The Athena Lunar Lander Also Fell Over on its Side

Rotating Black Holes are Packed with Energy. Here's How to Unlock It

When young stars form, they accumulate an accretion disk of gas and dust, which eventually forms planets. Typically, this process lasts less than 10 million years, as the increasing radiation from the star disperses the remaining material. However, recent observations from the James Webb Space Telescope have revealed a protoplanetary disk in a system estimated to be 30 million years old—three times longer than the expected lifespan. Scientists have already determined this is not a debris disk created by colliding planets, it’s an intriguing discovery that has forced a review of our model of planetary system and stellar evolution.

After a long ‘eclipse drought,’ lunar totality once again spans the Americas The end is in sight. If skies are clear, North and South America will witness a fine total lunar eclipse early Friday morning, March 14th. This is the first eclipse of 2025, and the first total lunar eclipse for the hemisphere since November 2022.

For the second time in a row, SpaceX lost the second stage of its Starship launch system during a flight test, while recovering the first-stage Super Heavy booster.

An X-ray signal has been detected at the very centre of the Helix Nebula, at the site of its central white dwarf star. It’s a burned out stellar remnant that doesn’t usually emit flashes of X-ray radiation but a new study has been analysing the outburst. The team of researchers think that the stellar corpse smashed into one of its surviving planets and that the X-rays are coming from the planetary debris as it falls onto the surface of the white dwarf.

An ultra-hot Neptune exoplanet has been observed by JWST and the image reveals dramatically different hemispheres. The planet orbits so close to its host start that it is tidally locked so one hemisphere remains facing the star. On this permanent daytime side, temperatures reach 2,000°C but the temperatures plummet on the daytime side. The observations show that the daytime side has bright reflective clouds on its cooler western hemisphere but not on its eastern side!

The Gaia Hypothesis theorizes that all of Earth's systems are tied together, making one large, living organism. While there's still some disagreement about whether or not that hypothesis is true, it is undeniable that many of Earth's systems are intertwined and that changes in one can affect another. As our technology advances, we are becoming more and more capable of detecting changes in those systems and how those changes affect other systems as well. A new proposal from a robotics expert at NASA's Jet Propulsion Laboratory (JPL) takes that exploration one step further by trying to develop a system that takes the "pulse" of a planet.

The mystery of Dark Matter endures. Despite sixty years of observation and research, scientists still haven't isolated the particle that accounts for roughly 85% of the Universe's mass. However, ongoing experiments and studies have provided insight into how this mysterious mass works. For instance, a research team led by a member of the Tokyo Metropolitan University relied on a new technique that has set new limits on the lifetime of Dark Matter (DM), bringing scientists a step closer to resolving this cosmological mystery.

Skeptics love to bring up one particular topic regarding long-term human space exploration - radiation. So far, all of the research completed on it has been relatively limited and has shown nothing but harmful effects. Long-term exposure has been linked to an increase in cancer, cataracts, or even, in some extreme cases, acute radiation poisoning, an immediate life-threatening condition. NASA is aware of the problem and recently supported a new post-doc from MIT named Robert Hinshaw via the Institute for Advanced Concepts (NIAC) program. Dr. HHinshaw'sjob over the next year will be to study the effectiveness of an extreme type of mitochondria replacement therapy to treat the long- and short-term risks of radiation exposure in space.

The Moon's getting to be a popular place. Firefly's Blue Ghost touched down on March 2nd in Mare Crisium. It's the first privately built lander to land safely and begin its mission. The little spacecraft set down safely in an upright, stable position and sent back an "I'm here" signal right away.

The dividing line between gas giant planets and failed stars is blurry at best. The isolated planetary-mass object SIMP J013656.5+093347.3 could be either one. The distinction is largely semantic. However we choose to label and define it, the object displays a surprisingly complex atmosphere for an isolated object without any stellar energy input.

In an effort to conserve Voyager 2's dwindling energy and extend the spacecraft's mission, NASA has shut down another of its instruments. They did it with the Plasma Spectrometer in October 2024, and it won't be the last. In March, Voyager 2's Low-Energy Charged Particle instrument will be powered down.

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.

The study was led by Rodolfo A. Salido and Haoqi Nina Zhao, a bioengineer and an environmental analytical chemist at the University of California San Diego (UCSD), respectively. They were joined by researchers from multiple UCSD programs and centers, the University of Denver, the Chiba University-UC San Diego Center for Mucosal Immunology Allergy and Vaccines (cMAV), Space Research Within Reach, the Baylor College Center for Space Medicine, the Blue Marble Space Institute of Science (BMSIS), the Biotechnology and Planetary Protection Group at NASA JPL, and the Astronaut Office at NASA Johnson.

The study was a collaborative effort with astronauts aboard the ISS, who swabbed 803 different surfaces – 100 times that of previous surveys – to get a census of microbes aboard the station. The researchers identified which bacterial species and chemicals were present in each sample and created three-dimensional maps to illustrate where each of them was found and how they might be interacting. Their results indicate that the ISS has a much lower diversity of microbes compared to human-built environments on Earth.

NASA astronaut Catherine (Cady) Coleman, Expedition 26 flight engineer, is pictured with a stowage container and its contents in the Harmony node of the International Space Station. Credit: NASA

Overall, the team found that chemicals from cleaning products and disinfectants were ubiquitously throughout the station and that astronauts mostly introduce microbes aboard the ISS through shed human skin cells. They also found that different modules hosted different microbial communities and chemical signatures based on the module’s use. For example, dining and food preparation areas contained more food-related microbes, whereas the ISS’s space toilet contained more urine- and fecal matter-related microbes and bioproducts of metabolism (metabolites).

“We noticed that the abundance of disinfectant on the surface of the International Space Station is highly correlated with the microbiome diversity at different locations on the space station,” said Zhao in a Cell Press release. These results suggest that more microbes from Earth could help improve astronaut health. Said Salido:

“Future built environments, including space stations, could benefit from intentionally fostering diverse microbial communities that better mimic the natural microbial exposures experienced on Earth, rather than relying on highly sanitized spaces. If we really want life to thrive outside Earth, we can’t just take a small branch of the tree of life and launch it into space and hope that it will work out. We need to start thinking about what other beneficial companions we should be sending with these astronauts to help them develop ecosystems that will be sustainable and beneficial for all.” 

The team found that microbial communities were less diverse aboard the ISS than most places on Earth, except where urban, industrialized, and isolated environments (i.e., hospitals) were concerned. They further found that ISS surfaces lacked free-living environmental microbes usually found in soil and water. Similar to the well-documented benefits gardening has for the human immune system, the researchers conclude that incorporating these microbes and their substrates into the ISS could improve astronaut health without sacrificing hygiene.

Astronauts on the International Space Station experience an orbital reboost. Credit: NASA/ESA

“There’s a big difference between exposure to healthy soil from gardening versus stewing in our own filth, which is kind of what happens if we’re in a strictly enclosed environment with no ongoing input of those healthy sources of microbes from the outside,” said co-author Robin Knight, a computational microbiologist and professor at UCSD and leader of the Knight Lab.

Looking to the future, the researchers hope to refine their analyses to detect potentially pathogenic microbes and how environmental metabolites could be used as indicators for astronaut health. The team claims that these methods could also help improve the health of people living and working in similarly sterile environments on Earth.

This research was supported by the National Institute of Health (NIH), the Alfred P. Sloan Foundation, UCSD, the Center for the Advancement of Science in Space (CASIS), and the ISS National Laboratory. The paper detailing their findings, “The International Space Station has a unique and extreme microbial and chemical environment driven by use patterns,” was published on February 27th in the journal Cell.

Further Reading: EurekAlert!

The post For the Sake of Astronaut Health, Should we Make the ISS Dirtier? appeared first on Universe Today.

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.

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:

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