Science

On Thursday January 30th, astronauts Suni Williams and Butch Wilmore are doing a 6.5-hour spacewalk outside the International Space Station. Among other goals, they’ll be collecting surface samples from the station to analyze for the presence of microbes.

The ISS “surface swab” is part of the ISS External Microorganisms project. It was developed to understand how microorganisms are transported by crew members to space. It also seeks to understand what happens to those “mini-critters” in the space environment.

The “bugs” that the two astronauts bring back in for analysis will come from areas on the space station near life-support system vents. The idea is to figure out if the station releases those microbes through the vents. Scientists also want to know the size of the release population, and where else they show up on the station.

The Microbes Experiment

Researchers seek to understand how microbes exist and thrive in space and planetary environments. At the moment, the best analog for those is on the ISS, particularly its exterior. So, when microbes find their way out, people want to know how long they survive the radiation. Do quick temperature changes affect them? What else happens to them? Also, scientists want to know if microbes manage to reproduce and how the environment changes that.

Samples from the ISS surface get frozen in special containers and eventually get returned to Earth. Once in the lab, they’re analyzed using culture-independent techniques such as next-generation deoxyribonucleic acid (DNA) sequencing to measure microbial community. Functional pathways in these microbial communities are characterized by targeting multi-gene analysis. This approach allows for a comprehensive assessment of the microbial diversity and metabolic function without cultivation. The samples collected at different locations or during different EVA opportunities allow investigators to map the microbial diversity of ISS external surfaces.

A member of the ISS External Microorganisms payload development team demonstrates removing a swab from the sampling caddy that is used by an astronaut during a spacewalk. A crew member uses the swabbing tool to collect microbes in samples from the exterior surface of the International Space Station at various locations. Results could inform preparations for future human exploration missions to the Moon and Mars. Credit: NASA. Why Test for Microbes?

While people have been flying to and from space for decades now, the scientific community still has significant gaps in knowledge about understanding how microbes get released, how they thrive, and what their life cycles are in space. In particular, the ISS sees many visiting vehicles each year, and astronauts move around freely inside. Those activities likely increase the microbe population both inside and out.

Collecting microbes and analyzing them allows scientists to assess the types and numbers of microorganisms living on the outer shell of a spacecraft. The larger goal is to supply more information under the guidelines of NASA’s policy on Planetary Protection Requirements for Human Extraterrestrial missions. There are still many questions to be answered, including: what are the acceptable levels of microbial life? Which ones make it out through the vents? What are acceptable contamination rates? While NASA has designed this mission to answer those and other questions, the Russian space agency Roscosmos is also making similar investigations to sample the Russian side of the station. That resulted in the discovery of non-spore-forming bacteria growing on the outer skin of the station.

The results of microbe analysis from this and other microorganism collections could affect spacecraft design and spacesuit changes. This becomes doubly important when people venture out onto the surface of Mars, for example. While we see no direct evidence of life there now, it could be there and likely existed in the past. Not only do we want to avoid contaminating astronauts with that life, we also want to avoid (as much as possible) bringing Earth life to Mars. This same research has applications in other fields, such as agriculture and pharmaceuticals.

Info on the Space Walk

This isn’t the first time the ISS has been tested for exterior microbial life, and the long-term study is necessary. The planned sampling to be mission undertaken by Williams and Wilmore is officially called Spacewalk 92 and should start at 8 a.m. on January 30th. NASA will provide live coverage of the walk (check here for more information), which will also conduct some other maintenance on the station along with the sampling activities.

For More Information

Astronauts Set to Swab the Exterior of Station for Microbial Life
Space Station Research Explorer

The post Astronauts are Going to Check if There are Microbes on the Outside of the Station appeared first on Universe Today.

When an exoplanet is discovered, scientists are quick to describe it and explain its properties. Now, we know of thousands of them, many of which are members of a planetary system, like the well-known TRAPPIST-1 family of planets.

Patterns are starting to emerge in these exoplanetary systems, and in new research, a team of scientists says it’s time to start classifying exoplanet systems rather than just individual planets.

The paper is “Architecture Classification for Extrasolar Planetary Systems,” and it’s available on the pre-print site arxiv.org. The lead author is Alex Howe from NASA’s Goddard Space Flight Center. The authors say it’s time to develop and implement a classification framework for exoplanet systems based on our entire catalogue of exoplanets.

“With nearly 6000 confirmed exoplanets discovered, including more than 300 multiplanet systems with three or more planets, the current observational sample has reached the point where it is both feasible and useful to build a classification system that divides the observed population into meaningful categories,” they write.

The authors explain that it’s time for a systemic approach to identifying patterns in exoplanet systems. With almost 6,000 exoplanets discovered, scientists now have the data to make this proposition worthwhile.

Artist’s rendition of a variety of exoplanets featured in the new NASA TESS-Keck Survey Mass Catalog, the largest, single, homogenous analysis of TESS planets released by any survey thus far. Credit: W. M. Keck Observatory/Adam Makarenko

What categories do the authors propose?

The first step is necessarily broad. “The core of our classification system comes down to three questions for any given system (although, in several cases, we add additional subcategories). Does the system have distinct inner and outer planets?” the authors write.

Next comes the question of Jupiters. “Do the inner planets include one or more Jupiters?” After that, they ask if the inner planets contain any gaps with a period ratio greater than 5. That means if within the gaps between the inner planets, are there any instances where the ratio of the orbital periods of two hypothetical planets occupying those gaps would exceed 5? Basically, that boils down to asking if the absence of planets in specific regions in the inner solar system is related to unstable orbits.

These three questions are sufficient to classify nearly all of the exoplanet systems we’ve discovered.

“We find that these three questions are sufficient to classify ~97% of multiplanet systems with N ?3 planets with minimal ambiguity, to which we then add useful subcategories, such as where any large gaps occur and whether or not a hot Jupiter is present,” the authors write.

The result is a classification scheme that divides exoplanet systems into inner and outer regimes and then divides the inner regimes into dynamical classes. Those classes are:

• Peas-in-a-pod systems where the planets are uniformly small
• Warm Jupiter systems containing a mix of large and small planets
• Closely-space systems
• Gapped systems

There are further subdivisions based on gap locations and other features.

“This framework allows us to make a partial classification of one- and two-planet systems and a nearly complete classification of known systems with three or more planets, with a very few exceptions with unusual dynamical structures,” the authors explain.

In summary, the classification scheme first divides systems into inner and outer planets (if both are detected). Systems with more than three inner planets are then classified based on whether their inner planets include any Jupiters and whether (and if so, where) their inner planets include large gaps with a period ratio >5. Some systems have other dynamical features that are addressed separately from the overall classification system.

This is a quick reference chart for the new system of classifying planetary system architectures, with representative model systems for each category. Each row is one planetary system, where the horizontal spacing corresponds to the orbital period, and the point sizes correspond to planet sizes. Colours correspond to planet type: Jupiters (>6 Earth radii, red), Neptunes (3.5-6 Earth radii, gold), Sub-Neptunes (1.75-3.5 Earth radii, blue), and Earths (<1.75 Earth radii, green). Image Credit: Howe et al. 2025.

The classification system is based on NASA’s Exoplanet Archive, which listed 5,759 exoplanets as of September 2024. It’s a comprehensive archive, but it also contains some questionable exoplanets drawn from papers that can sometimes be inaccurate, poorly constrained, or even contradicted by subsequent papers. The researchers filtered their catalogue to remove data they considered unusable. As a result, they removed 2% of the exoplanets in their archive.

They also filtered out some of the stars because of incomplete data, which meant that planets around those stars were removed, too. Planets orbiting white dwarfs and pulsars were removed, as were planets orbiting brown dwarfs. The idea was to “represent the population of planets orbiting main sequence stars,” as the authors explain.

This table from the research shows the number of confirmed planetary systems by multiplicity after the researchers applied all of their filters. Image Credit: Howe et al. 2025.

As the table above makes clear, most exoplanet systems contain only a single detected planet. 78% of them host only one planet, often a hot Jupiter, though selection effects play a role in the data. Jupiters are a key planet type in nature and in the classification scheme.

“As expected, Jupiter-sized planets are far less likely to occur in multiplanet systems at periods of <10 days and virtually none do at <5 days, as indicated by the near-coincidence of the two Jupiter distributions at those periods. Meanwhile, roughly half of all other planet types and even a third of Jupiters at periods >10 days occur in multiplanet systems,” the authors explain.

This figure shows the cumulative distributions of confirmed exoplanets with orbital periods. It compares the total numbers of planets (dashed) to those in single-planet systems (solid). “Hot Jupiters show far fewer companions than other planet types, as illustrated by the near-coincidence of the two Jupiter distributions at <10 days,” the authors explain.

The classification system does a good job of capturing the large majority of exoplanet system architectures. However, there are some oddballs, including the WASP-148 system, the only known system with a hot Jupiter and a nearby Jupiter companion. “Given the high detection probability of such a companion and the fact that 10 hot Jupiters are known to have smaller nearby companions, this points to an especially rare subtype of system and potential unusual migration processes,” the authors write.

This table presents the seven oddballs in NASA’s Exoplanet Archive according to the classification scheme. Image Credit: Howe et al. 2025.

Though exoplanet systems seem to be very diverse, this classification scheme shows that there’s a lot of uniformity in the patterns. Even though there’s a large diversity of planet types, most inner systems are either peas-in-a-pod systems or warm Jupiter systems. “Only a tiny minority of N ?3 systems (9 out of 314) prove difficult to classify into one of these two categories,” the authors write.

Like much exoplanet science, this system is hampered by detection biases. We struggle to detect small planets like Mars with our current capabilities. There could be more of them hiding in observed exoplanet systems. There are more detection problems, too, like planets on long orbits. However, the scheme is still valuable and interesting.

“This classification scheme provides a largely qualitative description of the architectures of currently observed multiplanet systems,” the authors explain. “The next step is to understand how such systems are formed, and, perhaps equally important, why other dynamically plausible systems are not present in the database.”

One outcome concerns the peas-in-a-pod systems. Since they’re so prevalent, scientists are keen to develop theories on their formation.

The system also has implications for habitability. The outcomes show that in peas-in-a-pod systems, the planets are often too close to main sequence stars to be habitable. Conversely, these same types of systems around M-dwarfs likely have planets in their stars’ habitable zones. “This may suggest that the majority of habitable planets reside around lower-mass stars in peas-in-a-pod systems,” the authors explain. That brings up the familiar problem of flaring and red dwarf habitability.

Another problem this classification scheme highlights concerns super-Earth habitability. “Most planets in peas-in-a-pod systems are super-Earths, rather than Earth-sized, and may be too large for the canonical definition of a habitable planet,” the authors write.

In their conclusion, the researchers explain that exoplanet systems seem to have clear organizing principles that we can use to classify distinct types of solar systems.

“Though far from complete, we believe this classification provides a better understanding of the population as a whole, and it should be fertile ground for future studies of exoplanet demographics and formation,” the researchers conclude.

The post It’s Time to Start Classifying Exoplanetary Systems appeared first on Universe Today.

I thought I was clever when I decided that an alternative word for a woke person could be a “Passive Progressive”, but then was told that woke people aren’t passive because they create a lot of noise and kerfuffle. I still like my new term, though, as by “passivity” I meant “performativeness”.  That is, a woke person espouses progressive Leftist ideals but does not do anything to enact them, ergo the passivity.

But I digress. While poring through some scientific literature yesterday, I came upon an issue of The American Naturalist from July 2022. This used to be one of the go-to journals for publishing evolutionary biology, and I was a corresponding editor for a while, but in my view it’s slipped a bit. This issue, with its special section on “Nature, data, and power” is about as ideologically captured as you can get. And this was three years ago! Well, capture started well before that. If you want to read any of these articles, just click on the screenshots below (there are two because the section is so long. There are other real science papers not soaked in politics, but I haven’t put them down.

Which paper is your favorite?

 

Doctors who mourned the loss of a single speech or YouTube video are fine with the the mass censorship of public scientists.

The post Well Well Well, We Want Them Infected Doctors Are OK With Censorship After All first appeared on Science-Based Medicine.

Boom Supersonic’s XB-1 aircraft broke the sound barrier during three test runs, a step toward the possible return of supersonic commercial flights

Astronomers have found some pretty wild exoplanets. Some are balls of lava the temperature of hell, one is partially made of diamond, and another may rain molten iron. However, not all exoplanets are this extreme. Some are rocky, roughly Earth-sized worlds in the habitable zones of their stars.

Could simple Earth life survive on some of these less extreme worlds?

We currently describe a solar system’s habitable zone by liquid water. If a planet is at the right distance range from its star to host stable surface water, we consider it to be in the habitable zone. However, new research is taking a different approach by emphasizing the role a planet’s atmosphere plays in habitability.

The scientists behind this research tested their idea by seeing if microbes could survive on simulated worlds.

The new research is “The Role of Atmospheric Composition in Defining the Habitable Zone Limits and Supporting E. coli Growth.” It’s available on the pre-print site arxiv.org. The lead author is Asena Kuzucan, a post-doctoral researcher in the Department of Astronomy at the University of Geneva in Switzerland.

We’ve discovered close to 6,000 exoplanets in about 4,300 planetary systems. Our burgeoning catalogue of exoplanets makes us wonder about life. Is there life elsewhere, and are any of these thousands of exoplanets habitable?

Some have teased the possibility. TRAPPIST1-e and Proxima Centauri b are both rocky planets in the habitable zones of their stars. TOI-700 d orbits a small, cool star and may be in its habitable zone. There are many others.

The simple definition of the habitable zone is restricted to a planet’s distance from its star and if liquid water can persist on its surface at that distance. However, scientists know that a planet’s atmosphere plays a large role in habitability. A thick atmosphere on a planet outside the habitable zone could help it maintain liquid water.

“Each atmosphere uniquely influences the likelihood of surface liquid water, defining the habitable zone (HZ), the region around a star where liquid water can exist,” the authors write. Liquid water doesn’t guarantee that a world is habitable, however. In order to understand exoplanet habitability better, the researchers followed a two-pronged approach.

They started by estimating exoplanet surface conditions near the inner edge of a star’s HZ with different atmospheric compositions.

Next, they considered if Earth microbes could survive in these environments. They did lab experiments on E. coli to see how or if they could grow and survive. They focused on the different compositions of gas in these atmospheres. The atmospheric compositions were standard (Earth) air, pure CO2, N2-rich, CH4-rich, and pure molecular hydrogen.

Their experiments used 15 separate bottles, 3 for each of the 5 atmospheric compositions. Each bottle was inoculated with E. coli K-12, a laboratory strain of E. coli that is a cornerstone of molecular biology studies.

This simple graphic shows the atmospheric composition of the test bottles. Each bottle is a combination of different atmospheric composition and pressure. LB stands for Lysogeny broth, a nutrient source for E. coli K12. image Credit: Kuzucan et al. 2025.

“This innovative combination of climate modelling and biological experiments bridges theoretical climate predictions with biological outcomes,” they write in their research.

Along with their laboratory experiments, the team performed a series of simulations with different atmospheric compositions and planetary characteristics. “For each atmospheric composition we simulate, water is a variable component that can condense or evaporate as a function of the pressure/temperature conditions,” they write. For each atmospheric composition, they simulated planets at different orbital distances in order to define the inner edge of the HZ. They also varied the atmospheric pressure.

“Using 3D GCM (General Circulation Model) simulations, this study provides a first look at how these atmospheric compositions influence the inner edge of the habitable zone, offering valuable insights into the theoretical limits of habitability under these extreme conditions,” the authors explain.

This table from the research shows the planetary and stellar characteristics used in the GCM simulations. Image Credit: Kuzucan et al. 2025.

“Our findings indicate that atmospheric composition significantly affects bacterial growth patterns, highlighting the importance of considering diverse atmospheres in evaluating exoplanet habitability and advancing the search for life beyond Earth,” they write.

This figure shows the cell count for E. coli K12 in each simulated atmosphere. Image Credit: Kuzucan et al. 2025.

E. coli did surprisingly well in varied atmospheric compositions. Though there was a lag following inoculation as the E. coli adapted, cell density increased in some of the tests. The hydrogen-rich atmosphere did surprisingly well.

“By the first day after inoculation, cell densities had increased in standard air, CH4-rich, N2-rich, and pure H2 atmospheres,” the authors write. “While cell densities increased similarly in standard air, CH4-rich, and N2-rich atmospheres, a slightly stronger increase was observed in the pure H2 atmosphere. The rapid adaptation of E. coli to pure H2 suggests that hydrogen-rich atmospheres can support anaerobic microbial life once acclimatization occurs.”

Conversely to the H2 results, the CO2 results lagged. “Pure CO2, however, consistently presented the most challenging environment, with significantly slower growth,” the paper states.

Their results suggest that planets with anaerobic atmospheres that are dominated by H2, CH4, or
N2 could still support microbial life, even if the initial growth is slower than it is in Earth’s air. “The ability to adapt to less favourable conditions implies that life could persist on such planets, given sufficient time for acclimatization,” the authors write.

The CO2-rich atmosphere is the outlier in this work. “The consistently poor growth in pure CO2 highlights the limitations of this gas in supporting life, particularly for heterotrophic organisms like E. coli,” Kuzucan and her co-researchers write. However, the authors point out that some life forms can make use of CO2 as a carbon source in some environments. They explain that planets with these types of atmospheres could still host organisms adapted to them, like chemotrophs or extremophiles.

This work combines atmospheric and biological factors to understand exoplanet HZs. “One of our key objectives was to define the limits of the HZ for planets dominated by H2 and CO2 using 3D climate modelling, specifically the Generic PCM model,” the authors explain.

They found that H2 atmospheres have a warming effect, “pushing the inner edge of the HZ to further orbital distances than CO2-dominated atmospheres.” It could extend out to 1.4 AU at 5 bar, while the CO2 atmospheres at the same pressure were limited to 1.2 AU. “This demonstrates the profound impact of atmospheric composition on planetary climate and highlights how H2 atmospheres can extend the
habitable zone further from their host stars,” the researchers write.

Some of the atmospheres they tested are not likely to persist in nature, but the results are still scientifically valuable.

“Although some of the atmospheric scenarios presented here (1-bar H2 and CO2) are simplified, and
may not persist over geological timescales due to processes like hydrogen escape and carbonate-silicate cycling, they nonetheless provide valuable insights into the radiative effects of these gases on habitability,” write the authors.

We know atmospheres are extremely complex, and this research supports that. It also shows how resilient Earth life can be. “Overall, these results highlight both the resilience of E. coli in adapting to diverse atmospheric conditions and the critical role atmospheric composition plays in determining
microbial survival,” the authors explain in their conclusion. Though the authors acknowledge that their findings are rooted in an Earth-centric framework, the results have broader implications. Life could likely thrive in wildly different atmospheric compositions and conditions, according to these results.

“Thus, our study highlights the importance of atmospheric composition and pressure for habitability while acknowledging the limitations of our Earth-centric perspective,” they write.

“By exploring both atmospheric conditions and microbial survival, we gain a deeper understanding of the complex factors that influence habitability, paving the way for future research on the potential for life beyond our solar system.”

The post How Well Could Earth Life Survive on Exoplanets appeared first on Universe Today.

As humankind imagines living off-planet -- on the moon, Mars and beyond -- the question of how to sustain life revolves around the physical necessities of oxygen, food and water. We know there is water on the moon, but how do we find it? Researchers may help bring science fiction to reality by providing a divining rod to guide future space missions.

Researchers are able to test in parallel the effects of over 1500 active substances on cell metabolism. Their analysis also led to the discovery of previously unknown mechanisms for known medications. This approach might help scientists to better predict side effects and find additional uses for commercially available pharmaceuticals.

Can a computer learn a language the way a child does? A recent study sheds new light on this question. The researchers advocate for a fundamental revision of how artificial intelligence acquires and processes language.

Thirty years after the discovery of the first exoplanet, we detected more than 7000 of them in our Galaxy. But there are still billions more to be discovered! At the same time, exoplanetologists have begun to take an interest in their characteristics, with the aim of finding life elsewhere in the Universe. This is the background to the discovery of super-Earth HD 20794 d by an international team. The new planet lies in an eccentric orbit, so that it oscillates in and out of its star's habitable zone. This discovery is the fruit of 20 years of observations using the best telescopes in the world.

Scientists have developed a new optimization model to improve microgrid operation. This model adapts to unexpected changes in power supply and demand, ensuring stable and efficient energy systems. By addressing challenges like power outages and varying energy needs, this approach enhances the reliability and sustainability of microgrids, making it suitable for real-world use in areas with unstable power grids.

In a step towards developing advanced materials for functional coatings, a research group has developed a technology that combines structural color coating with super water-repellent properties. The structural color coating does not fade away like the conventional paints and exhibits self-cleaning properties. This was achieved by using hydrophobic melanin particles which provide structural color and water-repellence. The discovery marks a breakthrough in advanced materials for paints and coatings.

An environmentally-friendly preparation of plant material from pine could serve as a substitute for petroleum-based chemicals in polyurethane foams. The innovation could lead to more environmentally friendly versions of foams used ubiquitously in products such as kitchen sponges, foam cushions, coatings, adhesives, packaging and insulation. The global market for polyurethane totaled more than $75 billion in 2022.

A new one-minute video game is able to accurately and efficiently identify children with autism from those who have ADHD or are neurotypical.

A new study finds that prompts do a good job of getting drivers to engage with their environment and take over control of the vehicle when necessary while using partially automated driving systems -- with one exception. If drivers are deeply distracted, these system-generated prompts have little or no effect.

A new study finds that prompts do a good job of getting drivers to engage with their environment and take over control of the vehicle when necessary while using partially automated driving systems -- with one exception. If drivers are deeply distracted, these system-generated prompts have little or no effect.

Researchers propose a novel system that uses standing surface acoustic waves to separate circulating tumor cells from red blood cells with unprecedented precision and efficiency. The platform integrates advanced computational modeling, experimental analysis, and artificial intelligence algorithms to analyze complex acoustofluidic phenomena. The researchers included an innovative use of dualized pressure acoustic fields and strategically located them at critical channel geometry positions on a lithium niobate substrate. By means of acoustic pressure applied within the microchannel, the system design provides for the generation of reliable datasets.

The fact that the cold, dry Mars of today had flowing rivers and lakes several billion years ago has puzzled scientists for decades. Now, researchers think they have a good explanation for a warmer, wetter ancient Mars. Building on prior theories describing the Mars of yore as a hot again, cold again place, a team has determined the chemical mechanisms by which ancient Mars was able to sustain enough warmth in its early days to host water, and possibly life.

Space-time may hide a bizarre new kind of black hole that causes Einstein’s theory of gravity to fail – and could solve the mystery of dark energy

For the first time that we know of, mice with two fathers have survived to adulthood, but the methods used would be "unthinkable" to try in people