‘Worms in space’ experiment aims to investigate the biological effects of spaceflight
Universities of Exeter and Leicester collaborate on mission to send nematode worms to the International Space Station
University of Leicester
image:
The Fluorescent Deep Space Petri-Pod (FDSPP).
view moreCredit: University of Leicester/Space Park Leicester
A crew of tiny worms will be heading on a mission to the International Space Station in 2026 that will help scientists understand how humans can travel through space safely, using a Leicester-built space pod.
A team of scientists and engineers at Space Park Leicester, the University of Leicester’s pioneering £100 million science and innovation park, have designed and built a miniature space laboratory called a Petri Pod, based around the principle of the biological culture petri dish invented in 1887 and based upon earlier development work by the University of Exeter and Leicester, that will allow scientists on Earth to study biological organisms in space.
There is a burgeoning global drive for humans to colonise space, the Moon and other planets of our Solar System, but one of the challenges is the harmful effects of extended exposure to the effects of the space environment on human physiology. This includes microgravity which can lead to bone and muscle loss, fluid shift and vision problems in humans as well as radiation induced effects genetic damage, increased cancer risk, etc.
Hence life sciences experiments that investigate these effects on biology are an essential precursor to safe human space travel. The Fluorescent Deep Space Petri-Pod (FDSPP) has been developed by the Space Park Leicester team with the scientific lead Tim Etheridge at the University of Exeter and is tailored to the unique constraints of the space-based biology research that is urgently needed.
The Petri Pod is a miniaturised hardware solution for performing remotely operated biological experimentation on multiple types of organisms, via fluorescent and white light imaging capabilities in deep space. It is a self-contained experiment within a housing measuring approximately 10x10x30cm and weighing around 3kg, containing 12 Petri-Pods for experiments, four of which can be actively imaged. Each Petri Pod maintains a trapped volume of air and a stable comfortable temperature for the organisms when the unit is exposed to the vacuum of space. The worms are provided with food and water by means of an Agar carrier and the trapped air is sufficient for the small organisms involved. A more advanced version with ‘life support’ for larger and more complex organisms or extended missions is planned for the future based around the existing system.
The flight system hardware, along with a spare, has been delivered to the USA and has successfully undergone acceptance testing during the last two weeks, prior to it being launched on a cargo flight to the International Space Station (ISS) in April 2026. Its first passengers will be C-Elegans Nematode Worms which have natural fluorescent markers in their heads. These will be installed just before launch. Initially, the experiment and worms will spend time inside the ISS before being deployed outside on an experimental platform to expose the Petri Pod to the vacuum and radiation of space along with the micro-gravity environment for at least a 15-week period. The eight non-imaged ‘Petri Pods’ will contain a variety of other biological test subjects e.g., micro-organisms, along with tests of various materials. The experiment will be returned to Earth from the ISS after exposure on a future cargo return flight.
During the experiment the health of the worms will be monitored using photographic stills and time-lapse video captured with miniature cameras and by exposure to white light, or by fluorescent stimulation using low powered lasers, under the control of onboard microcontroller units. The FDSPP will collect data on temperature and pressure inside and outside of the containment volumes (‘Petri Pods’), and characterise the background radiation by monitoring accumulated radiation dose. Data will be stored locally in the unit for download on its return to Earth and also relayed to the Earth ground station over the ISS downlink communication system. The mission is enabled by funding from the UK Space Agency and commercial launch and support by Voyager Technologies based in Houston USA.
Professor Mark Sims who acted a project manager for FDSPP at Leicester said: “The Fluorescent Deep Space Petri-Pod has been engineered using the electronic, engineering, software and science expertise of the Space Park Leicester team, based around the 65-year heritage of space experiments at Leicester. This mission to the International Space Station (ISS) will demonstrate the flight-readiness of FDSPP and we believe its success will help position the UK amongst the global leaders of life sciences research on future low Earth orbit, Lunar and Mars missions planned by Space Agencies and private companies.”
Professor Tim Etheridge, the principal investigator and science lead for the experiment from the University of Exeter said: “Performing biology research in space comes with many challenges but is vital to humans safely living in space. This hardware, made possible through strong collaboration between biologists around the world and engineers at Space Park Leicester, will offer scientists a new way to understand and prevent health changes in deep space on any launch vehicle.”
The Space Park Leicester team behind the Fluorescent Deep Space Petri-Pod (FDSPP).
The Fluorescent Deep Space Petri-Pod (FDSPP).
Credit
University of Leicester/Space Park Leicester
University of Leicester/Space Park Leicester
Scientists get a first look at the innermost region of a white dwarf system
X-ray observations reveal surprising features of the dying star’s most energetic environment
Massachusetts Institute of Technology
image:
A smaller white dwarf star (left) pulls material from a larger star into a swirling accretion disk. The pair is called an “intermediate polar,” and MIT astronomers used powerful telescopes to measure the system’s X-ray polarization for the first time, revealing key features at the center of its hottest, most extreme regions.
view moreCredit: Jose-Luis Olivares, MIT
Some 200 light years from Earth, the core of a dead star is circling a larger star in a macabre cosmic dance. The dead star is a type of white dwarf that exerts a powerful magnetic field as it pulls material from the larger star into a swirling, accreting disk. The spiraling pair is what’s known as an “intermediate polar” — a type of star system that gives off a complex pattern of intense radiation, including X-rays, as gas from the larger star falls onto the other one.
Now, MIT astronomers have used an X-ray telescope in space to identify key features in the system’s innermost region — an extremely energetic environment that has been inaccessible to most telescopes until now. In an open-access study published in the Astrophysical Journal, the team reports using NASA’s Imaging X-ray Polarimetry Explorer (IXPE) to observe the intermediate polar, known as EX Hydrae.
The team found a surprisingly high degree of X-ray polarization, which describes the direction of an X-ray wave’s electric field, as well as an unexpected direction of polarization in the X-rays coming from EX Hydrae. From these measurements, the researchers traced the X-rays back to their source in the system’s innermost region, close to the surface of the white dwarf.
What’s more, they determined that the system’s X-rays were emitted from a column of white-hot material that the white dwarf was pulling in from its companion star. They estimate that this column is about 2,000 miles high — about half the radius of the white dwarf itself and much taller than what physicists had predicted for such a system. They also determined that the X-rays are reflected off the white dwarf’s surface before scattering into space — an effect that physicists suspected but hadn’t confirmed until now.
The team’s results demonstrate that X-ray polarimetry can be an effective way to study extreme stellar environments such as the most energetic regions of an accreting white dwarf.
“We showed that X-ray polarimetry can be used to make detailed measurements of the white dwarf's accretion geometry,” says Sean Gunderson, a postdoc in MIT’s Kavli Institute for Astrophysics and Space Research, who is the study’s lead author. “It opens the window into the possibility of making similar measurements of other types of accreting white dwarfs that also have never had predicted X-ray polarization signals.”
Gunderson’s MIT Kavli co-authors include graduate student Swati Ravi and research scientists Herman Marshall and David Huenemoerder, along with Dustin Swarm of the University of Iowa, Richard Ignace of East Tennessee State University, Yael Nazé of the University of Liège, and Pragati Pradhan of Embry Riddle Aeronautical University.
A high-energy fountain
All forms of light, including X-rays, are influenced by electric and magnetic fields. Light travels in waves that wiggle, or oscillate, at right angles to the direction in which the light is traveling. External electric and magnetic fields can pull these oscillations in random directions. But when light interacts and bounces off a surface, it can become polarized, meaning that its vibrations tighten up in one direction. Polarized light, then, can be a way for scientists to trace the source of the light and discern some details about the source’s geometry.
The IXPE space observatory is NASA’s first mission designed to study polarized X-rays that are emitted by extreme astrophysical objects. The spacecraft, which launched in 2021, orbits the Earth and records these polarized X-rays. Since launch, it has primarily focused on supernovae, black holes, and neutron stars.
The new MIT study is the first to use IXPE to measure polarized X-rays from an intermediate polar — a smaller system compared to black holes and supernovas, that nevertheless is known to be a strong emitter of X-rays.
“We started talking about how much polarization would be useful to get an idea of what’s happening in these types of systems, which most telescopes see as just a dot in their field of view,” Marshall says.
An intermediate polar gets its name from the strength of the central white dwarf’s magnetic field. When this field is strong, the material from the companion star is directly pulled toward the white dwarf’s magnetic poles. When the field is very weak, the stellar material instead swirls around the dwarf in an accretion disk that eventually deposits matter directly onto the dwarf’s surface.
In the case of an intermediate polar, physicists predict that material should fall in a complex sort of in-between pattern, forming an accretion disk that also gets pulled toward the white dwarf’s poles. The magnetic field should lift the disk of incoming material far upward, like a high-energy fountain, before the stellar debris falls toward the white dwarf’s magnetic poles, at speeds of millions of miles per hour, in what astronomers refer to as an “accretion curtain.” Physicists suspect that this falling material should run up against previously lifted material that is still falling toward the poles, creating a sort of traffic jam of gas. This pile-up of matter forms a column of colliding gas that is tens of millions of degrees Fahrenheit and should emit high-energy X-rays.
An innermost picture
By measuring any polarized X-rays emitted by EX Hydrae, the team aimed to test the picture of intermediate polars that physicists had hypothesized. In January 2025, IXPE took a total of about 600,000 seconds, or about seven days’ worth, of X-ray measurements from the system.
“With every X-ray that comes in from the source, you can measure the polarization direction,” Marshall explains. “You collect a lot of these, and they’re all at different angles and directions which you can average to get a preferred degree and direction of the polarization.”
Their measurements revealed an 8 percent polarization degree that was much higher than what scientists had predicted according to some theoretical models. From there, the researchers were able to confirm that the X-rays were indeed coming from the system’s column, and that this column is about 2,000 miles high.
“If you were able to stand somewhat close to the white dwarf’s pole, you would see a column of gas stretching 2,000 miles into the sky, and then fanning outward,” Gunderson says.
The team also measured the direction of EX Hydrae’s X-ray polarization, which they determined to be perpendicular to the white dwarf’s column of incoming gas. This was a sign that the X-rays emitted by the column were then bouncing off the white dwarf’s surface before traveling into space, and eventually into IXPE’s telescopes.
“The thing that’s helpful about X-ray polarization is that it’s giving you a picture of the innermost, most energetic portion of this entire system,” Ravi says. “When we look through other telescopes, we don’t see any of this detail.”
The team plans to apply X-ray polarization to study other accreting white dwarf systems, which could help scientists get a grasp on much larger cosmic phenomena.
“There comes a point where so much material is falling onto the white dwarf from a companion star that the white dwarf can’t hold it anymore, the whole thing collapses and produces a type of supernova that’s observable throughout the universe, which can be used to figure out the size of the universe,” Marshall offers. “So understanding these white dwarf systems helps scientists understand the sources of those supernovae, and tells you about the ecology of the galaxy.”
This research was supported, in part, by NASA.
###
Written by Jennifer Chu, MIT News
Paper: “X-Ray Polarimetry of Accreting White Dwarfs: A Case Study of EX Hydrae”
https://iopscience.iop.org/article/10.3847/1538-4357/ae11b5
Journal
The Astrophysical Journal
Article Title
“X-Ray Polarimetry of Accreting White Dwarfs: A Case Study of EX Hydrae”
By AFP
November 20, 2025
This NASA image shows the interstellar comet 3I/ATLAS, circled in the center, as seen by the L'LORRI black-and-white imager on NASA's Lucy spacecraft - Copyright NASA/AFP NASA
Charlotte CAUSIT
A flying piece of cosmic rock or an alien threat? Comet 3I/ATLAS is hurtling through our solar system and captivating scientists and internet users alike, even prompting Kim Kardashian to ask NASA for answers.
Questions on whether the comet could actually be an alien spacecraft are coming from sources as varied as the reality TV star, a member of US Congress and a Harvard researcher, as well as from prominent conspiracy theorists.
But that theory has been shot down by NASA, which released new images of the comet on Wednesday after the speculation gained traction online.
“It’s amazing to see how people are really engaged in the discussion,” said Thomas Puzia, an astrophysicist who led the team at the Chilean observatory that made the discovery.
But, “it’s very dangerous and to a certain degree misleading to put speculations ahead of scientific process,” he told AFP in a thinly veiled criticism of another researcher who has been insisting for weeks that the extraterrestrial spacecraft hypothesis cannot be ruled out.
“The facts, all of them without exception, point to a normal object that is coming from the interstellar space to us,” he said.
He added the comet was “very exceptional in its nature, but it’s nothing that we cannot explain with physics.”
– Seeking signs of life –
Since its detection in July, the comet has generated intense speculation — unsurprisingly so, given it is only the third interstellar object foreign to our solar system ever discovered to be passing through.
The first was the Oumuamua comet, which sparked similar ripples of excitement and debate in 2017.
Even then, Harvard Professor Avi Loeb supported the theory that Oumuamua could be a spacecraft, a controversial position he later defended in a book.
He has now accused his scientific peers of lacking open-mindedness when it comes to Comet 3I/ATLAS.
“Obviously, it could be natural,” he told AFP. “But I said: we have to consider the possibility that it’s technological because if it is then the implications for humanity will be huge.”
NASA, however, did not agree.
“We want very much to find signs of life in the universe… but 3I/ATLAS is a comet,” said Amit Kshatriya, a senior NASA official, at a press conference on Wednesday.
The debate risked overshadowing the very real wonder that 3I/ATLAS represents, according to Puzia who said it offered “an unprecedented insight into an extrasolar system, potentially billions of years older than our own solar system.”
– ‘Goosebumps’ –
If there is one thing everyone agrees on, it is that 3I/ATLAS is anything but ordinary.
The comet holds many mysteries, particularly regarding its origin and exact composition, which scientists hope to unravel through close observation in the coming weeks as it gets closer to Earth.
This small, solid body composed of rock and ice from the far reaches of space could help us better understand how “planets might form” or even “how life might form around other stars in the Milky Way Galaxy in different times of the evolutionary history of the galaxy,” according to Puzia.
NASA scientist Tom Statler described having “goosebumps” when thinking about the comet’s origins.
“We can’t say this for sure, but the likelihood is it came from a solar system older than our own solar system itself,” he said. “It’s a window into the deep past, and so deep in the past that it predates even the formation of our Earth and our Sun.”
Unlike the two interstellar objects detected previously and only briefly studied, astronomers have had months to observe 3I/ATLAS.
And they hope this is just the beginning, thanks to improving technology for observation and detection.
“We should be finding many, many more of them every year,” Darryl Seligman of Michigan State University told AFP.
Theia and Earth were neighbors
New research suggests that the body that collided with Earth 4.5 billion years ago, creating the Moon, originated in the inner Solar System.
Max Planck Institute for Solar System Research
About 4.5 billion years ago, the most momentous event in the history of our planet occurred: a huge celestial body called Theia collided with the young Earth. How the collision unfolded and what exactly happened afterwards has not been conclusively clarified. What is certain, however, is that the size, composition, and orbit of the Earth changed as a result – and that the impact marked the birth of our constant companion in space, the Moon.
What kind of body was it that so dramatically altered the course of our planet's development? How big was Theia? What was it made of? And from which part of the Solar System did it hurtle toward Earth? Finding answers to these questions is difficult. After all, Theia was completely destroyed in the collision. Nevertheless, traces of it can still be found today, for example in the composition of present-day Earth and Moon. In the current study, published on November 20, 2025, in the journal Science, researchers led by the Max Planck Institute for Solar System Research (MPS) and the University of Chicago use this information to deduce the possible “list of ingredients” of Theia – and thus its place of origin.
Quote:
The composition of a body archives its entire history of formation, including its place of origin.
Thorsten Kleine, Director at MPS and co-author of the new study
The ratios in which certain metal isotopes are present in a body are particularly revealing. Isotopes are variants of the same element that differ only in the number of neutrons in their atomic nucleus – and thus in their weight. In the early Solar System, the isotopes of a given element were probably not evenly distributed: At the outer edge of the Solar System, for example, the isotopes occurred in a slightly different ratio than near the Sun. Information about the origin of its original building blocks is thus stored in the isotopic composition of a body.
Searching for traces of Theia in Earth and Moon
In the current study, the research team determined the ratio of different iron isotopes in Earth and Moon rocks with unprecedented precision. To this end, they examined 15 terrestrial rocks and six lunar samples that astronauts from the Apollo missions brought back to Earth. The result is hardly surprising: as earlier measurements of the isotope ratios of chromium, calcium, titanium, and zirconium had already shown, Earth and Moon are indistinguishable in this respect.
However, the great similarity does not allow any direct conclusions about Theia. There are simply too many possible collision scenarios. Although most models assume that the Moon was formed almost exclusively from material from Theia, it is also possible that it consists primarily of material from the early Earth's mantle or that the rocks from Earth and Theia mixed inseparably.
Reverse engineering of a planet
In order to learn more about Theia, the researchers applied a kind of reverse engineering for planets. Based on the matching isotope ratios in today's terrestrial and lunar rocks, the team played through which compositions and sizes of Theia and which composition of the early Earth could have led to this final state.
In their investigations, the researchers looked not only at iron isotopes, but also at those of chromium, molybdenum, and zirconium. The different elements give access to different phases of planetary formation.
Long before the devastating encounter with Theia, a kind of sorting process had taken place inside the early Earth. With the formation of the iron core, some elements such as iron and molybdenum accumulated there; they were afterwards largely absent from the rocky mantle. The iron found in the Earth's mantle today can therefore only have arrived after the core was formed, for example on board of Theia. Other elements such as zirconium, which did not sink into the core, document the entire history of our planet's formation.
Meteorites as a reference
Of the mathematically possible compositions of Theia and the early Earth that result from the calculations, some can be ruled out as implausible.
Quote:
The most convincing scenario is that most of the building blocks of Earth and Theia originated in the inner Solar System. Earth and Theia are likely to have been neighbors.
Timo Hopp, MPS scientist and lead author of the new study
While the composition of the early Earth can be represented predominantly as a mixture of known meteorite classes, this is not the case with Theia. Different meteorite classes originated in different areas of the outer Solar System. They therefore serve as reference material for the building material that was available during the formation of the early Earth and Theia. In the case of Theia, however, previously unknown material may also have been involved. Researchers believe this material’s origin to be closer to the Sun than Earth. The calculations therefore suggest that Theia originated closer to the Sun than our planet.
Journal
Science
Method of Research
Experimental study
Subject of Research
Not applicable
Article Title
The Moon-forming impactor Theia originated from the inner Solar System
Article Publication Date
20-Nov-2025
Giant impactor Theia formed in the inner Solar System
Summary author: Walter Beckwith
By tracking the isotopic fingerprints of iron in lunar and terrestrial rocks, researchers trying to understand the origin of the Moon’s mysterious progenitor add evidence to the idea that it came from the inner Solar System. According to the findings, Theia – the Mars-sized planetary body that collided with Earth to form the Moon – was born possibly closer to the Sun than to Earth. The Moon is believed to have formed when Theia collided with early Earth roughly a hundred million years after the formation of the Solar System. Most models of this process suggest that the Moon is mostly composed of materials derived from this ancient impactor. If Theia had a different isotopic makeup from Earth, it would be expected that the Moon would as well. Such isotopic variations can reveal where a planetary body originated in the Solar System, which could provide insight into the origin of Theia. However, analyses of lunar rock show that the Moon and Earth are nearly identical in their isotopic compositions for many elements. Although competing models have attempted to explain this similarity, the absence of clear isotopic differences and uncertainty over which processes caused this have made it challenging to determine where Theia originally formed. Here, Timo Hopp and colleagues conducted new high-precision iron isotope analyses of lunar samples, terrestrial rocks, and meteorites representing the isotopic reservoirs from which Theia and proto-Earth might have formed. According to the analysis, Earth and the Moon have indistinguishable iron isotopic compositions and both fall within that of non-carbonaceous meteorites, which are thought to represent material formed in the inner Solar System. Integrating these results with previous isotopic data for other elements and performing mass balance calculations for Theia and proto-Earth, Hopp et al. conclude that Theia likely originated in the inner Solar System and formed even closer to the Sun than proto-Earth.
Journal
Science
Article Title
The Moon-forming impactor Theia originated from the inner Solar System
Article Publication Date
20-Nov-2025
This moss survived 9 months directly exposed to the elements of space
Cell Press
image:
A reddish-brown sporophyte can be seen at the top center of a leafy gametophore. This capsule contains numerous spores inside. Mature sporophytes like these were individually collected and used as samples for the space exposure experiment conducted on the exposure facility of the International Space Station (ISS).
view moreCredit: Tomomichi Fujita
Mosses thrive in the most extreme environments on Earth, from the peaks of the Himalayas to the sands of Death Valley, the Antarctic tundra to the lava fields of active volcanoes. Inspired by moss’s resilience, researchers sent moss sporophytes—reproductive structures that encase spores—to the most extreme environment yet: space. Publishing in the Cell Press journal iScience on November 20, their results show that over 80% of the spores survived 9 months outside of the International Space Station (ISS) and made it back to Earth still capable of reproducing, demonstrating for the first time that an early land plant can survive long-term exposure to the elements of space.
“Most living organisms, including humans, cannot survive even briefly in the vacuum of space,” says lead author Tomomichi Fujita of Hokkaido University. "However, the moss spores retained their vitality after nine months of direct exposure. This provides striking evidence that the life that has evolved on Earth possesses, at the cellular level, intrinsic mechanisms to endure the conditions of space.”
The concept of space moss occurred to Fujita while studying plant evolution and development. He was struck by moss’s ability to colonize even the harshest environments on Earth. “I began to wonder: could this small yet remarkably robust plant also survive in space?”
To find out, Fujita’s team subjected Physcomitrium patens, a well-studied moss commonly known as spreading earthmoss, to a simulated a space environment, including high levels of UV radiation, extreme high and low temperatures, and vacuum conditions.
They tested three different structures from the moss—protenemata, or juvenile moss; brood cells, or specialized stem cells that emerge under stress conditions; and sporophytes, or encapsulated spores—to find out which had the best chance of surviving in space.
“We anticipated that the combined stresses of space, including vacuum, cosmic radiation, extreme temperature fluctuations, and microgravity, would cause far greater damage than any single stress alone,” says Fujita.
The researchers found that UV radiation was the toughest element to survive, and the sporophytes were by far the most resilient of the three moss parts. None of the juvenile moss survived high UV levels or extreme temperatures. The brood cells had a higher rate of survival, but the encased spores exhibited ~1,000x more tolerance to UV radiation. The spores were also able to survive and germinate after being exposed to −196°C for over a week, as well as after living in 55°C heat for a month.
The team suggested that the structure surrounding the spore serves as a protective barrier, absorbing UV radiation and blanketing the inner spore both physically and chemically to prevent damage. The researchers note that this is likely an evolutionary adaptation that allowed bryophytes—the group of plants to which mosses belong—to transition from aquatic to terrestrial plants 500 million years ago and survive several mass extinction events since then.
To see if this adaptation could make the sporophytes fit for the actual conditions of space, the team sent the spores beyond the stratosphere.
In March 2022, the researchers sent hundreds of sporophytes to the ISS aboard the Cygnus NG-17 spacecraft. Once they arrived, the astronauts attached the sporophyte samples to the outside of the ISS, where they were exposed to space for a total of 283 days. The moss then hitched a ride back to Earth on SpaceX CRS-16 in January 2023 and was returned to the lab for testing.
“We expected almost zero survival, but the result was the opposite: most of the spores survived,” says Fujita. “We were genuinely astonished by the extraordinary durability of these tiny plant cells.”
Over 80% of the spores survived their intergalactic journey, and all but 11% of the remaining spores were able to germinate back in the lab. The team also tested the chlorophyll levels of the spores and found normal levels for all types, with the exception of a 20% reduction in chlorphyll a—a compound which is particularly sensitive to changes in visual light, but this change didn’t seem to impact the health of the spores.
“This study demonstrates the astonishing resilience of life that originated on Earth,” says Fujita.
Curious how much longer the spores could have survived in space, Fujita’s team used the data from before and after the moss’s expedition to create a mathematical model. They predicted that the encased spores could have survived for up to 5,600 days—approximately 15 years—under space conditions. However, they emphasize that this number is just a rough estimate, and that a larger data set is needed to make more realistic predictions for how long moss could survive in space.
The researchers hope that their work helps advance research on the potential of extraterrestrial soils for facilitating plant growth and inspires exploration into using mosses to develop agricultural systems in space.
"Ultimately, we hope this work opens a new frontier toward constructing ecosystems in extraterrestrial environments such as the Moon and Mars,” says Fujita. “I hope that our moss research will serve as a starting point.”
Germinated moss spores after space exposure.
Credit
Dr. Chang-hyun Maeng and Maika Kobayashi
The space exposure unit used for the experiment next to a 100-yen coin for scale.
Credit
Tomomichi Fujita
This work was supported by DX scholarship Hokkaido University, JSPS KAKENHI, and the Astrobiology Center of National Institutes of Natural Sciences.
iScience, Maeng et al., “Extreme environmental tolerance and space survivability of the moss, Physcomitrium patens” https://www.cell.com/iscience/fulltext/S2589-0042(25)02088-7
iScience (@iScience_CP) is an open access journal from Cell Press that provides a platform for original research and interdisciplinary thinking in the life, physical, and earth sciences. The primary criterion for publication in iScience is a significant contribution to a relevant field combined with robust results and underlying methodology. Visit: http://www.cell.com/iscience. To receive Cell Press media alerts, contact press@cell.com.
Journal
iScience
Method of Research
Experimental study
Subject of Research
Not applicable
Article Title
Extreme Environmental Tolerance and Space Survivability of the Moss, Physcomitrium patens
Article Publication Date
20-Nov-2025
Prediction of optic disc edema progression during spaceflight
JAMA Ophthalmology
About The Study:
The findings of this study suggest crewmembers who did not develop optic disc edema (ODE) on flight day 30 were unlikely to develop clinically concerning ODE on flight day 150. The data suggest that optical coherence tomography imaging during spaceflight missions provides an opportunity to predict the magnitude of ODE that may develop during a longer-lasting mission.
Corresponding Author: To contact the corresponding author, Brandon R. Macias, PhD, email brandon.r.macias@nasa.gov.
To access the embargoed study: Visit our For The Media website at this link https://media.jamanetwork.com/
(doi:10.1001/jamaophthalmol.2025.4635)
Editor’s Note: Please see the article for additional information, including other authors, author contributions and affiliations, conflict of interest and financial disclosures, and funding and support.
# # #
Embed this link to provide your readers free access to the full-text article This link will be live at the
Journal
JAMA Ophthalmology
Modeling of electrostatic and contact interaction between low-velocity lunar dust and spacecraft
image:
Fig. 1. A diagram illustrating the phenomenon of charged dust particles being attracted or repulsed to the charged spacecraft on the lunar surface. Background image republished from ESA-ATG.
view moreCredit: Space: Science & Technology
Due to the unique conditions of the space environment and abundant resources, the field investigation and study of the Moon, Earth’s sole natural satellite, represent a crucial milestone in China’s forthcoming deep space endeavors. The successful collection of lunar soil by the Chang’E-5 mission signifies the next phase of the lunar exploration program, which aims to establish a preliminary research station on the lunar south pole. Highly adhesive fine dust particles with an adhesion strength of 0.1 to 1.0 kN/m2, which originate from the regolith, disperse throughout the lunar surface. These particles exhibit a lasting attraction and subsequent persistent adhesion to the surface of spacecraft or spacesuits. The accumulation of highly adhesive dust on spacecraft presents a serious issue to hinder long-term extravehicular activity and the establishment of a permanent station on lunar surface. In contrast to the immediate physical damage caused by hypervelocity (> 1.0 km/s) impacts, this adhesion observed at low- velocity (0.01 to 100 m/s) collisions can more unobtrusively and mortally degenerate the performance of equipment. In recent years, many interaction models have been developed to forecast the adhesion and ejection dynamics of lunar dust on various surfaces. Most researches on the electrostatic force applied on dust particles near the surface use point-charge approximation. Although this simplification makes the simulation easier, the error can be large due to the polarization of dust induced by the image charge. In a research article recently published in Space: Science & Technology, scholars from Beijing Institute of Technology, China Academy of Space Technology, and Chinese Academy of Sciences together propose a theoretical model aimed at comprehensively analyzing the dynamics of adhesion and escape phenomena occurring during low-velocity impacts between charged dust particles and spacecrafts enveloped by a plasma sheath which serves as a crucial step toward understanding the mechanism of lunar dust pollution.
First, the model of electrostatic force is demonstrated. As depicted in Fig. 1, dominated by the photoelectron effect induced by solar ultraviolet and x-ray radiation, the spacecraft and lunar regolith on lunar dayside typically charge positive. As a result, a photoelectron sheath forms above the surface. On the nightside, the spacecraft and regolith usually are negatively charged since the collection of plasma electrons. Due to the higher average thermal velocity of electrons compared to ions, a Debye sheath consequently forms around the vehicle. Besides, the exposure to the solar wind, the lunar plasma wake, and plasma in the magnetotail lobes and plasma sheet also electrically charges the spacecraft and regolith. This study only focuses on the interaction between charged particles and spacecraft within the confines of the plasma sheath, while the interaction between dust with plasma can be safely neglected. Considering the significant difference in size between the vehicle and the dust particle, the vehicle can be assumed as an infinite conducting plane coated with a dielectric layer, as depicted in Fig. 2. A dielectric dust particle, characterized by its radius Rp, uniform surface charge density σp, and permittivity εp, is positioned at a distance d above the surface. The distance between the surface of the coating and the shell is triple the Debye length (Rd) of plasma sheath. The potential of the shell is denoted by κ and is usually defined as the reference potential. The decay of potential in the sheath follows an exponential pattern. Hence, the distribution of the electric potential field within the plasma sheath can be expressed as: φ0 = κ exp[-(z-3Rd)/Rd], E0 = κ/Rd·exp[-(z-3Rd)/Rd], 0 ≤ z ≤ 3Rd. The electrostatic force FE is composed of 3 components: electric field force FEF, dielectrophoretic force FD, and image force FI, i.e., FE = FEF + FD + FI. The expression for FEF can be given by E0 with x = 0, y = 0, z = d + Rp multiplying the free charge Qp carried by the particle. FD is expressed using dyadic tensor notation. The multipole image force FI that acts on the induced multipole moments can be mathematically expressed considering the distance between the source point and the field point.
Then, the model of adhesive–elastic–plastic collision is demonstrated. In the present study, although lunar dust particles have extremely small size, irregular shape, and high hardness, they can be equivalently simplified to a spherical particle according to the conservation of normal contact force. The spacecraft coating consists of a Kapton layer. According to a dimensionless discriminant parameter μT, the commonly acknowledged JKR model which is useful for the analysis of collisions involving soft materials characterized by high interface energy can be utilized to describe the adhesive behavior of dust particles in this study. Additionally, in the context of low-velocity collisions, it is crucial to consider the energy dissipation caused by the plastic deformation of the coating. Based on the Thornton’s adhesive–elastic–plastic model, in which the adhesive energy dissipation is described by the JKR model, the process of low-speed collision can be divided into 3 distinct stages: the adhesive–elastic loading stage, the adhesive–elastic–plastic loading stage, and the adhesive–elastic unloading stage. Figure 3 depicts the distribution of contact stress between the dust and coating, referred to as p(r), throughout the various stages. In the adhesive–elastic loading stage (see Fig. 3A), the relationship between the JKR pressure distribution p(r), the relative compression δ, and the contact force P1 in the first stage can be mathematically expressed as
As illustrated in Fig. 3B, during the adhesive–elastic–plastic loading stage, the normal contact force P2 is formulated and simplified as
In the unloading stage (see Fig. 3C), the correlation between the contact force P3 and the contact radius a continues to closely adhere to the JKR model with an irrecoverable displacement δp:
Finally, results and discussion are presented. As for electrostatic force, that a dielectric coating with a high thickness and low permittivity can effectively reduce the electrostatic force between charged dust and spacecraft can be inferred from the variation in the electrostatic force FE between the charged particle and the coated ground plane. Figure 5 illustrates the variation in the theoretical and simulated electrostatic force between the charged particle and the coated ground plane, considering various important parameters of the particle. It can be summarized that for dimensionless distance d/Rp ≥ 1 the electrostatic force between a charged particle and a coated ground plane can be approximated as F ≈ K Rp2 σp2 / (1 + d/Rp)2. Besides, results also show that the surface charge density plays a more significant role than the spacecraft potential. In the context of low-velocity collisions, a larger size of particle results in a higher maximum coefficient of restitution. The adhesive van der Waals force rather than electrostatic attraction force predominantly influences the adhesion of lunar dust during the low-velocity collision process, if the surface charge density σp is below 0.1 mC/m2. It can be inferred that the low-interface-energy coating, which can be created by employing low-surface-energy material and increasing the surface roughness, is effective to decrease the difficulty of dust removal. When it comes to the interaction between low-velocity charged particle and spacecraft, it is important to acknowledge that the final adhesion of particles to the spacecraft is not solely determined by the initial collision. Adhesion to the surface occurs only when the initial velocity of a negatively charged particle is within the range of the critical adhesion and escape velocities. At last, the conclusion is drawn that the theory presented in this study offers a framework for investigating various issues pertaining to the accumulation of charged dust particles. It can be applied to analyze phenomena such as dust deposition in electrostatic precipitators and the adhesion of energetic powder to mixer walls and serves as a basis for predicting and mitigating dust adhesion. Future research will focus on the integration of irregular shapes of dust, the plasma environment, and solar radiation effect into the interaction model.
DOI
Fig. 2. Geometric representation of a charged dust particle positioned above a spacecraft surface with a coating layer.
Credit
Space: Science & Technology
SETI Institute invites applications for the 2026 Mino Postdoctoral Fellowship
This research program offers an exceptional opportunity for talented early-career scientists worldwide.
SETI Institute
image:
Mino in front of the infrared telescope being assembled in Japan. Deep inside is Mino’s core instrument, the FIRP.
view moreCredit: Image Credit: Hisako Matsubara.
SETI Institute Invites Applications for the 2026 Mino Postdoctoral Fellowship
November 20, 2025, Mountain View, CA -- The SETI Institute is pleased to open the call for applications for the 2026 Mino Postdoctoral Fellowship. This research program offers an exceptional opportunity for talented early-career scientists worldwide to contribute significant advances in the following fields:
- Origins of life and prebiotic chemistry
- Biophysics and the nature of life
- Planetary habitability and environmental limits on life
- Coevolution of life and planetary environments across spatiotemporal scales
- Modeling and theory of life-environment systems
- Comparative studies of Earth, solar system worlds, and exoplanets
- AI/ML applied to origins, nature of life, and habitability research
The successful candidate will advance (i) their field in novel ways using one, or a combination of the following approaches: advanced data analytics, novel instruments and technologies, laboratory research, fieldwork and expeditions, ground and space-based telescopes, theory, modeling, and experimentation; and (ii) the mission of the SETI Institute: to lead humanity’s quest to understand the origins and prevalence of life and intelligence in the universe and share that knowledge with the world.
“The Mino Fellowship supports pioneering research at the frontiers of life’s origins and the limits of habitability,” said Dr. Nathalie Cabrol, Director of the Carl Sagan Center for Research at the SETI Institute. “We are looking for early-career scientists who are ready to push boundaries, connect disciplines, and bring new insight to one of humanity’s most fundamental questions: how life emerges, evolves, and persists in the universe.”
Applications open on November 20, 2025, and must be submitted by January 16, 2026.
The Mino Fellowship offers mentorship in a collaborative environment with leading researchers, access to the SETI Institute's advanced facilities, and the opportunity to engage with top Silicon Valley technologists. Fellows will receive a stipend of $85,000, as well as research and travel allowances and medical benefits.
The Mino Fellowship is a full-time, two-year program, with an option for a one-year extension based upon approval. Applicants must hold a PhD in a relevant field by the start of the Fellowship and have a proven track record of research. Relocation in the Bay Area is preferred.
Click here for more information on the Mino Postdoctoral Fellowship and its application details.
About Minoru Freund
Minoru Freund (February 3, 1962 – January 17, 2012) was an accomplished physicist whose work crossed boundaries. He led pioneering efforts in nanoscale materials and neuroscience at NASA Ames Research Center. He contributed to earlier projects at NASA Goddard Space Flight Center, the Air Force Research Laboratory, and the SETI Institute, always seeking the next frontier in knowledge. He held a PhD from the Swiss Institute of Technology in Zürich (1990). Mino's peers and colleagues celebrated Mino for imagining science differently, finding connections between fields others kept apart, and asking daring questions about life, environment, and intelligence.
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