Japan's private space company ispace experienced another setback on Thursday 5th June when its Resilience lunar lander crashed into the surface of the Moon, marking the company's second consecutive failed landing attempt in just over two years.

The Full Moon

(Credit : Gregory H. Revera)

The uncrewed spacecraft was attempting to touch down in Mare Frigoris, or the "Sea of Cold," a vast basaltic plain in the Moon's northern region around 3:17 p.m. ET on June 5th. More than 500 ispace employees, shareholders, and government officials watched anxiously at a public viewing event in Tokyo as flight data was suddenly lost less than two minutes before the scheduled touchdown time.

*Mare Frigoris is located just north of Mare Imbrium, and stretches east to north of Mare Serentatis.

(Credit : NASA)

According to ispace officials, the preliminary data suggests the lander's laser rangefinder experienced delays in obtaining accurate distance measurements to the lunar surface, preventing Resilience from slowing down for a safe landing. The spacecraft had successfully descended from about 100 kilometres to 20 kilometres above the surface and fired its main engine as planned, but something went wrong during the final critical phase.

“Based on these circumstances, it is currently assumed that the lander likely performed a hard landing on the lunar surface.” - ispace spokesperson This failure is somewhat similar to ispace's first attempt in April 2023, when their Hakuto-R lander also crashed during its final descent. However, company executives stressed that while both missions failed due to altitude measurement issues, the specific technical problems appear to be different.

Resilience had launched in January aboard a SpaceX Falcon 9 rocket alongside Firefly Aerospace's Blue Ghost lander, which took a faster trajectory to the Moon and successfully landed in March this year. The Japanese spacecraft chose a slower, more fuel-efficient route that took nearly five months to reach its destination.

The December 11th launch of a Falcon 9 rocket with the first Hakuto R. mission (Credit : SpaceX/ispace)

The mission carried significant scientific value, including a four-wheeled rover built by ispace's Luxembourg based subsidiary and five external payloads worth $16 million, featuring experiments from Japanese companies and a Taiwanese university. The lander was also contracted by NASA to collect lunar regolith samples during what was planned to be a 14-day surface mission.

Despite the setback, ispace isn't giving up. The company has already secured funding for a third attempt and is collaborating with US-based Draper on the Apex 1.0 lander, scheduled to target the Moon's far side as soon as 2027. The commercial space race to the Moon continues, but Thursday's crash serves as another reminder of just how challenging lunar exploration remains.

Source : 

• iSpace Mission Website

In this series we are exploring NASA's top five challenges as detailed in its Civil Space Shortfall Ranking, which is basically NASA's Christmas wish list. These are the technologies that NASA believes we need to develop if we want to go to space…and stay there.

And we'll start with number five: high-powered robotics.

Space is hard. There's no doubt about that. It's completely unlike any environment we have ever faced on the Earth. Explorers in space, whether human or robotic, have to tackle literally out-of-this-world challenges. For example, there are extreme temperature fluctuations. One minute it could be hot enough to boil water, and the next minute cold enough to freeze nitrogen. Without thick atmospheres to balance and distribute heat, within the inner solar system you're at the mercy of the Sun: if you're in sunlight, it's generally going to be too warm, and if you're in the shade, it's hundreds of degrees colder. In the outer solar system? It's just...cold. Always, miserably cold.

And then there's the dust. On the Earth, dust is irritating – it makes us sneeze and it can jam up gears or wheels or cause your breaks to make that loud SQUEEEL sound. But in space dust is next-level. The surface of the Moon is covered in a fine powder, regolith, that is both tiny and, microscopically, fully of tiny, jagged edges. This dust can worm itself through even our best-sealed compartments, or just get carried along for the ride – where it immediately just sticks to everything.

And hey, who doesn't love a dose of deadly radiation every single second of every single day? Without a protective magnetic field and the security blanket of a nice thick atmosphere, operations on the Moon and Mars require constant exposure to cosmic rays, tiny charged particles slamming through the universe. Cosmic rays are caused by super-energetic events like supernovae and active galactic nuclei, and a typical cosmic ray particle is traveling somewhere around 99.999999% the speed of light. That's a lot of nines, and a lot of trouble. These cosmic rays can fry electronics and snip apart DNA.

And yeah, we've been sending robots into this extreme environment for decades, but if we want a more permanent presence on the Moon and Mars, we have to do better. For sure, we've had some huge successes, like the Cassini mission that spent 13 years in orbit around Saturn, or the Mars Exploration Rovers – Spirit and Opportunity – which lasted years longer than their planned 90-day missions. Those missions produced an enormous amount of science results, like the fact that we now have firm evidence that liquid water once existed on the Martian surface. We have been able to gather this evidence with the instruments on our rovers like rock abrasion tools and alpha particle X-ray spectrometer, in addition to a good old-fashioned camera.

But the presence of liquid water in the Martian past has opened up a powerful, difficult question: did Mars once harbor life? Unfortunately our current suite of robotic instruments are too limited to tell us. We need to be able to dig deeper into the soil, survey more regions, and bring more powerful instruments to answer that burning question.

This isn't just limited to Mars rovers. In general, every robot we send into space has a limited lifespan, is not meant to be repaired, and is extremely limited in what it can do. And still, those missions cost hundreds of millions, or even billions, of dollars, because we're trying to battle all those hostile environmental factors.

On the Earth, we've made great strides in making larger and more powerful robots. We have heavy-duty robots that assemble cars, and we have versatile ones that can walk like humans.

To make more impressive robots, designers have focused on increasing the power density: the amount of energy that robots can store and send through their various parts and systems. These systems include sensing, actuation (moving various bits and parts around), and aviation (like flight control). The more power you have available to all these systems, the more you can do. But if we rank power density on a scale, like a wind-up toy being a 1 and a Kaiju-killing Jaeger a 10, our robotic space probes are like a…3. Maybe 4 if we're being generous.

It's not just about having a big battery pack or solar cell. We need the ability to get this power to a robot's subsystems. We need more powerful electric motors, gearing, and drive train components. We need more capable sensors, with more dynamic range, more perception, more force. We need long-lived power distribution systems; you know, like cables and wires. We need more powerful computers to drive this all.

And, if this weren't enough, we need future robots to be modular, so that we can easily swap out components to allow the robot to fulfill a new mission objective, and we need our robots to be repairable and maintainable, because we simply can't build up a healthy lunar or Martian infrastructure with single-shot craft.

In fact, we probably need space-based robots that are even more capable and more power-dense than their current terrestrial cousins. Meaning that our goal isn't just to make current top-of-the-line Earth robots capable of facing the dangers and challenges of space environments. No, we need EVEN BETTER.

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Across the universe, some of the most dramatic events occur when a black hole meets a neutron star. A neutron star is the ultra-dense remains of a massive star that exploded—imagine all the mass of our Sun compressed into a sphere just a few tens of kilometres wide. When a black hole and neutron star spiral toward each other, the result is one of nature's most violent spectacles.

Before diving into their collision, it's worth understanding just how extreme these objects are. A black hole is a region of space where gravity is so strong that nothing, not even light can escape once it crosses the "event horizon." Black holes form when the most massive stars collapse at the end of their lives, creating a point of infinite density surrounded by this inescapable boundary.

A neutron star, meanwhile, is what forms when a slightly less massive star explodes in a supernova. The explosion is so violent that it crushes protons and electrons together into neutrons, creating matter so dense that a teaspoon would weigh about 6 billion tons on Earth. These city-sized spheres spin incredibly fast—sometimes hundreds of times per second—and have magnetic fields trillions of times stronger than Earth's.

Central neutron star at the heart of the Crab Nebula

(Credit : ESA/Hubble)

Researchers at Caltech led by Caltech assistant Professor of theoretical astrophysics Elias Most, used powerful supercomputers to simulate what happens in the final moments before a collision between these two types of objects. About one second before the black hole swallows the neutron star, something remarkable occurs: the neutron star's surface cracks open, like an eggshell! The black hole's immense gravity stretches and tears the neutron star's crust, creating "starquakes" similar to earthquakes on our planet. When the surface cracks, the neutron star's magnetic field—which can be billions of times stronger than Earth's—gets violently shaken. This creates ripples called Alfvén waves that eventually produce a burst of radio signals that future telescopes might detect.

As the neutron star gets closer to the black hole, even more extreme physics takes over. When the neutron star finally plunges into the black hole, it creates what scientists call "monster shock waves,” the most powerful shock waves predicted in the universe. These are like cosmic tsunamis, starting small but growing into incredibly violent bursts of energy.

Perhaps most surprisingly, the simulations revealed something never seen before: the birth of a black hole pulsar. When the black hole consumes the neutron star, it also absorbs the neutron star's powerful magnetic field. But black holes don't want this magnetic baggage, so they essentially fling it around as they spin, creating magnetic winds that sweep through space like a lighthouse beam. This creates a brief cosmic lighthouse that lasts less than a second, emitting bursts of X-rays and gamma rays before going dark forever.

These simulations help astronomers know what to look for when scanning the skies. While we've detected gravitational waves from black hole collisions using instruments like LIGO (Laser Interferometer Gravitational-wave Observatory), we haven't yet seen the light shows that might accompany neutron star-black hole mergers. The research suggests that these cosmic crashes might produce detectable radio signals both when the neutron star cracks and when the monster shock waves form. Future telescopes, including Caltech's planned array of 2,000 radio dishes in Nevada, might be able to catch these brief cosmic screams.

The Livingston Observatory of LIGO (Credit : Caltech/MIT/LIGO) Scientists are now working to detect these mergers up to a minute before they happen using gravitational wave detectors. This would give astronomers precious time to point their telescopes at the right spot in the sky to catch the light show that accompanies these cosmic catastrophes.

Scientists are now working to detect these mergers up to a minute before they happen using gravitational wave detectors. This would give astronomers precious time to point their telescopes at the right spot in the sky to catch the light show that accompanies these cosmic catastrophes.

Source : 

• Star Quakes and Monster Shock Waves

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On the surface (you're welcome for the joke), Venus isn't even close to being hospitable to life. But that's not the end of the story.

This planet has by far the hottest surface temperatures in the solar system, beating out even Mercury, even though Venus is twice as far away from the Sun. That's because of a runaway greenhouse effect which unfolded…eh, we're not exactly sure, but somewhere between a few hundred million and a few billion years ago – there's a debate here. But it doesn't matter when exactly for our purposes; what matters is that it happened, and now the planet is choked to death in its own noxious atmosphere, with atmospheric pressures at the surface over 900 times greater than the Earth at sea level.

So super high pressure, and temperatures anywhere from 900 degrees Fahrenheit (480 Celsius) on the high end to a balmy…847 Fahrenheit / 450 Celsius on the cool end.

Here's the thing. There is no version of any kind of life in any form that we can possibly imagine existing under those conditions. I know that the universe is larger than our imagination, and there's always room for surprises, but…phew, even that's stretching it.

No, where we're really interested with Venus is in its atmosphere. The higher up you climb in altitude, the cooler the temperatures, until you're all the way in space, which is also bad but in the opposite way as the surface. But right in the middle, at an altitude between 50 and 60 kilometers, the temperatures are….fine. Comparable to the range of temperatures that we see on the Earth. And the air pressures are…fine. Comparable to the range of pressures that we see on the Earth.

The atmosphere itself is…not so fine. It's mostly carbon dioxide, which hey, it's what plants crave, but also a lot of nitrogen. And ultraviolet radiation breaks down the molecules in the upper atmosphere to make a host of really, really nasty stuff, like sulfuric acid, hydrogen sulfide, and chlorine.

So yes, you could walk outside and breath the air, and it would dissolve you from the inside out.

Life in the atmosphere of Venus has to have a really strange biochemistry. And in September of 2020 a group of astronomers claimed to detect the presence oflarge quantities of phosphine in the Venusian atmosphere. Now phosphine is an interesting molecule. It's quite stinky, and on Earth it's a byproduct of anaerobic bacteria (which is part of the reason that marshes and swamps are less than pleasant places to visit).

There ARE ways to produce phosphine without bacteria, and in fact Jupiter makes loads of it all the time, because of that planet's super-high temperatures and pressures – properties that Venus lacks. PLUS phosphine breaks down easily in UV light, so for it to be present in great quantities means that it has to be actively replenished and produced.

Cue…a giant mess. The news caused a tremendous uproar, with outlets around the world picking up on the tantalizing possibility. But then those pesky OTHER scientists shot back, arguing that the original research was flawed and used an improper analysis of background noise. Then the original authors updated their results and doubled-down. Then the astronomers working the telescope itself chimed in. Then others claimed that the signal was just getting confused for sulfur dioxide. Then…

Like I said, a giant mess, that even today isn't fully resolved. From what I can tell from the literature, the general stalemate sort-of-community-consensus that Venus probably doesn't have phosphine, and if it does, it's at levels far lower than the original claim.

Case closed? Not quite. NASA is developing two – that's right TWO – Venus missions to investigate further, because honestly there's only so much we can get from remote observations and the small scattering of probes we've (and by that I mean the Soviets) have been able to squeeze down to the surface for short-term visits.

One mission isDAVINCI, which will be an orbiter and an atmospheric probe. The other isVERITAS, an orbiter designed to map the surface in high resolution (which will also tell us a lot about the atmosphere). Don't worry, both missions have been delayed because NASA is kind of going through a thing at the moment.

The prospects of life on Venus seem rather low. But it's not zero. And long ago, before the greenhouse catastrophe, Venus was likely very similar to Earth. After all, we're made from the same material and have very similar properties – it's not an outrageous stretch of the imagination.

And some strange form of life may have gotten a start and evolved to adapt to the changing climate. Venusian life couldn't use water, it's way too hot for that. But they may use droplets of ammonium sulfite or sulfuric acid dispersed through the Venusian clouds. This life would be extremely simple, perhaps even lacking cell membranes and just consisting of self-replicating molecules that use UV radiation as an energy source.

This life may alter the chemical composition of the Venusian atmosphere, explaining several mysteries like the extra oxygen in the cloud layers, and extra amounts of sulfur dioxide where it shouldn't be based on simple chemical models.

I suppose it's worth a closer look after all.

Mars has received considerable attention in the past few decades, thanks to the many robotic missions exploring it to learn more about its past. NASA and China plan to send astronauts/taikonauts there in the coming decades, and commercial space companies like SpaceX hope to send passengers there sooner. This presents several significant challenges, one of the greatest being the lengthy transit times involved. Using conventional propulsion and low-energy trajectories, it takes 6 to 9 months for crewed spacecraft to reach Mars.

These durations complicate mission design and technology requirements and raise health and safety concerns since crews will be exposed to extended periods in microgravity and heightened exposure to cosmic radiation. Traditionally, mission designers have recommended nuclear-electric or nuclear-thermal propulsion (NEP/NTP), which could shorten trips to just 3 months. In a recent study, a UCSB physics researcher identified two trajectories that could reduce transits to Mars using the Starship to between 90 and 104 days.

The study was authored by Jack Kingdon, a graduate student researcher in the Physics Department at the University of California, Santa Barbara (UCSB). He is also a member of the UCSB Weld Lab, an experimental ultracold atomic physics group that uses quantum degenerate gases to explore quantum mechanical phenomena. The paper describing his work appeared in Scientific Reports (a Nature publication) on May 22nd, 2025.

Nuclear Propulsion

Per NASA's Moon to Mars mission architecture, the need for safer, more rapid transportation is paramount. Many proposals have been made for nuclear propulsion to reduce transits to Mars to 90 days. These include NASA's Cold War era concept, the Nuclear Engine for Rocket Vehicle Application (NERVA), and modern-day concepts like the Demonstration Rocket for Agile Cislunar Operations (DRACO) - being developed by NASA and DARPA - and the high-power electric plasma Variable Specific Impulse Magnetoplasma Rocket (VASIMR) proposed by Ad Astra.

Since its inception, research into nuclear propulsion has generally fallen into one of two camps: nuclear-thermal and nuclear-electric propulsion (NTP/NEP). The former relies on a nuclear reactor to heat hydrogen propellant, turning it into a hot plasma that is channeled to generate thrust, while the latter relies on a nuclear reactor to power a Hall-Effect engine. These concepts offer high acceleration (delta-v) and steady specific impulse (Isp), respectively, and using them together in the form of bimodal propulsion combines the benefits of both.

Many researchers consider the technology the only means to reduce transit times to the point that a mission will fall within NASA's career radiation limit of ~600 millisieverts (mSv). Kindgon's study challenges this prevailing assumption and advances the theory that a 90-day transfer can be achieved using conventional propulsion. This mission architecture could be realized while space agencies and commercial space entities wait for more advanced concepts to be developed. As Kingdon told Universe Today via email:

"This proposal's main advantage is that it only uses technology that exists or is close to existing. VASIMIR & NEP are very far from existing (for real missions in space), primarily as they all require giant in space nuclear reactors which will be technically tough and politically even tougher to develop. NTP is almost certainly more expensive than chemical even though the tech does exist, and it does not offer significant advantages."

Mission Outline

As outlined on its website, conference presentations, and user manual, the SpaceX mission architecture consists of six Starships travelling to Mars. Four of these spacecraft will haul 400 metric tons (440 U.S. tons) of cargo while two will transport 200 passengers. Based on the Block 2 design, which has a 1500 metric ton (1650 U.S. ton) propellant capacity, the crewed Starships will require 15 tankers to fully refuel in Low Earth Orbit (LEO). The cargo ships would require only four, since they would be sent on longer low-energy trajectories.

Once the flotilla arrives at Mars, the Spaceships will refuel using propellant created in situ using local carbon dioxide and water ice. When the return window approaches, one of the crew ships and 3-4 cargo ships will refuel and then launch into a Low Mars Orbit (LMO). The cargo ships will then transfer the majority of their propellant to the crew ship and return to the surface of Mars. The crew ship would then depart for Earth, and the process could be repeated for the other crew ship.

Kingdon calculated multiple trajectories using a Lambert Solver, which produces the shortest elliptical arc in two-body problem equations (aka. Lambert's problem). The first would depart Earth on April 30th, 2033, taking advantage of the 26-month periodic alignment between Earth and Mars. The transit would last 90 days, with the crew returning to Earth after another 90-day transit by July 2nd, 2035. The second would depart Earth on July 15th, 2035, and return to Earth after a 104-day transit on December 5th, 2037.

As Kingdon explained, the former trajectory is the most likely to succeed:

"The optimal trajectory is the 2033 trajectory - it has the lowest fuel requirements for the fastest transit time. A note that may not be obvious to the layreader is that Starship can very easily reach Mars in ~3 months - in fact it can in any launch window, over a fairly wide range of trajectories. However Starship may impact the Martian atmosphere too fast (although we do not know, and likely SpaceX don't either actually how fast Starship can hit the Martian atmosphere and survive). The trajectories discussed are ones that I am confident Starship will survive."

Challenges Remain

This study not only offers reduced transits to Mars but also addresses a key issue identified in the SpaceX mission architecture. This is the problem of the Starship's mass budget, which was identified in a previous study by a team of engineers from the German Aerospace Center (DLR), the University of Bremen, and the Chair of Space Systems at the Technical University of Dresden. After conducting a trajectory optimization, they found that the current plans did not yield a return flight opportunity due to a too large system mass.

In short, they found that once refueled on the surface, the Starship would not have sufficient thrust to achieve escape velocity and a trans-Earth-injection (TEI) maneuver. The addition of additional tankers to refuel in LMO addresses this issue by allowing the Starship to top up before breaking orbit from Mars.

Nevertheless, Kingdom acknowledges that there are still challenges that must be overcome before 90-day transits will be possible:

"There are two major challenges with this architecture, and those problems are also inherent to the current SpaceX Mars mission plan. Starship as a system must work - the failures on flight 7,8 & 9 must be overcome, and improvements to vehicle performance must be made, along with development of life support systems and orbital refuelling but these are all planned."

Another major challenge is the prospect of building refueling stations on Mars' surface. According to SpaceX's plan, propellant would be manufactured using a Sabatier reactor, where methane and oxygen are produced via a chemical reaction between hydrogen and carbon dioxide. No one has ever attempted to manufacture cryogenic propellants on another planet, and this presents all manner of unknowns.

"[T]his will be a tough problem, but again likely less hard of a problem than catching a 70m tall skyscraper with giant mechanical arms," said Kingdon. "If SpaceX gets close to its intended near-term performance goals for Starship, this architecture is feasible."

Further Reading: 

• Nature

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The challenge in the search for habitable worlds is clear. We need to be able to identify habitable worlds and distinguish between biotic and abiotic processes. Ideally, scientists would do this on entire populations of exoplanets rather than on a case-by-case basis. Exoplanets' natural thermostats might provide a way of doing this.

"Within just a few decades, the search for potentially habitable and inhabited exoplanets has evolved from science fiction to a central scientific pursuit for the exoplanet community," the authors of new research write. With more than 5,000 confirmed exoplanets, the scientific focus is shifting from detecting exoplanets to characterizing them. The new work shows how atmospheric carbon dioxide could play a central role in understanding exoplanets.

The new research is titled "Detecting Atmospheric CO2 Trends as Population-Level Signatures for Long-Term Stable Water Oceans and Biotic Activity on Temperate Terrestrial Exoplanets." It will be published in the Astrophysical Journal, and the lead author is Janina Hansen from the ETH Zurich Institute for Particle Physics & Astrophysics. The research is available at arxiv.org.

Terrestrial planets like Earth have a natural thermostat called carbonate-silicate (Cb-Si) weathering feedback. The Cb-Si feedback is a geochemical cycle that regulates a planet's atmospheric CO₂ content over long geological timescales.

When CO₂ builds up in the atmosphere, the atmosphere warms. This creates more evaporation and rainfall. Carbonic acid is a weak acid formed in the atmosphere when water combines with carbon dioxide. When a warming atmosphere creates more rain, it also creates more carbonic acid.

Carbonic acid falls on the planet's surface, weathering silicate rocks and removing carbon. The carbon is eventually washed into the sea, where it's taken up in the shells of marine organisms. It falls to the sediment on the ocean floor and is ultimately sequestered back into the crust with help from plate tectonics. The creatures that absorb the carbon into their shells as calcium carbonate play a key role. The carbon in their shells becomes limestone.

This process is enhanced in a warming atmosphere, meaning it eventually removes more carbon from the atmosphere until it cools and the cycle slows again. Volcanic activity can release carbon back into the atmosphere, completing the cycle. Scientists think Earth's Cb-Si feedback has allowed our planet to maintain surface water and habitability for billions of years.

Earth as seen from NASA's Apollo 17 mission. Are there other worlds out there like ours? If they do, they likely have their own carbonate-silicate cycles.

Image Credit: By NASA/Apollo 17 crew; taken by either Harrison Schmitt or Ron Evans - Public Domain, https://commons.wikimedia.org/w/index.php?curid=43894484

The question is, can the Cb-Si cycle be understood in terms of a population of exoplanets? If it can be, then exoplanet scientists will have a powerful new way of understanding exoplanets without spending an inordinate amount of time examining them individually. With the help of upcoming missions, the Cb-Si cycle could be the tool scientists need.

"Identifying key observables is essential for enhancing our knowledge of exoplanet habitability and biospheres, as well as improving future mission capabilities," the researchers write. "While currently challenging, future observatories such as the Large Interferometer for Exoplanets (LIFE) will enable atmospheric observations of a diverse sample of temperate terrestrial worlds."

The researchers explain that the Cb-Si weathering feedback is a well-known habitability marker and a potential biological tracer. The cycle creates specific CO₂ trends in terrestrial atmospheres. In their work, they explore the idea that they can identify CO₂ trends specific to biotic or abiotic planet populations. They did it by creating simulated exoplanet populations based on geochemistry-climate predictions. The exoplanets are all exo-Earth Candidates (EEC) because they're the most conservative habitable zone planet candidates. The simulations involved EEC populations of 10, 30, 50, and 100 planets.

Their simulations include stellar flux, different F, G, and K-type stars within 20 parsecs of the Sun, and various atmospheric CO₂ partial pressures. "With this, we aim to produce planet populations which remain close to an Earth-Sun-like environment," the researchers explain. The researchers then retrieved their results based on the observational power of the proposed LIFE mission, which is intended to detect atmospheric biosignatures.

"We observe a robust detection of CO₂ trends for population sizes NP ≥ 30 and all considered spectrum quality scenarios S/N = [10, 20] and R = [50, 100] in both biotic and abiotic cases," the authors write. NP is the number of planets or population size, and S/N and R describe the quality of the atmospheric spectrum acquired by LIFE. S/N is the signal-to-noise ratio, while R is spectral resolution.

This figure illustrates some of the results. The top shows biotic trends, and the bottom shows abiotic trends. The dark blue biotic trends indicate a relationship between incident flux and atmospheric CO₂ pressure, which shows that a Cb-Si weathering feedback cycle is present. The study aims to identify this relationship and trend among exo-Earth candidates.

Image Credit: Hansen et al. 2025. ApJ

That means that Cb-Si weathering feedback trends are robustly detectable in populations of 30 or greater exo-Earth candidates, where the signal-to-noise ratio is either 10 or 20 and the spectral resolution is at least 50 or 100. S/N ratios of 10 or 20, and resolutions of 50 are modest observational capabilities.

"We demonstrate the ability of future missions like LIFE, or similar mid-infrared interferometer concepts, to enable population-level characterization of temperate terrestrial atmospheres and find that Cb-Si cycle driven CO2 trends, as a population-wide habitability signature, can readily be detected in a modest population of thermal emission spectra," the authors write.

This illustration shows LIFE, the Large Interferometer For Exoplanets. The five-satellite constellation is designed to detect and characterize the atmospheres of dozens of Earth-like worlds.

Image Credit: ETH Zurich/LIFE Initiative.

Their work had some limitations, though, which the researchers readily point out. For example, there are systematic biases in CO₂ partial pressure measurements, and those measurements are critical to identifying the trends. Their atmospheric model is also simplified and contains only H₂0, CO₂, and N₂, which are essential features of Earth's atmosphere, but not a complete picture. "The inclusion of additional species, such as CH₄ or O₃, would influence the self-consistent modelling of planetary atmospheres, impacting thermal structures and surface conditions," the researchers explain.

The end result is that this method shows promise for identifying population-level CO2 trends in populations of only 30 EECs. If scientists can do that, they can narrow down the targets worthy of in-depth study and characterization.

This is just the beginning of population-wide characterization of exoplanets and their biotic and abiotic signatures. Instead of looking for the "smoking-gun" signature of life on single worlds, we may be able to detect and identify life through large statistical patterns across numerous worlds. In that case, this work also shows how telescopes with modest observational capabilities can "filter through" the exoplanet population, sparing valuable and expensive observing time on more powerful observatories.

However, there's still more work to do before we get to that stage. The method needs to be tested against more diverse atmospheres.

"Further studies, which test atmospheric characterization performance against broad atmospheric diversity, are essential to prepare next-generation observational facilities to provide robust and accurate constraints of atmospheric as well as planetary parameters," the researchers explain in their conclusion.

"Efforts like these will pave the way toward assessing the commonness of habitable worlds or even global-scale biospheres outside of our Solar System," they conclude.

How can humanity use the developing Lunar Gateway as an appropriate starting point for advancing human space exploration beyond the Moon? This is what a recent study presented at the 56^th Lunar and Planetary Science Conference (LPSC) hopes to address as a team of researchers evaluated a myriad of ways that Lunar Gateway could be used as a testbed for future technologies involving sending humans to Mars and Ceres. This study has the potential to help scientists, engineers, astronauts, and mission planners develop novel strategies for advancing long-term human space exploration.

For the study, Malaya Kumar Biswal, who is the Founder & CEO of Acceleron Aerospace, and  Ramesh Kumar V, the Founder and CEO of Grahaa Space, build on recent research they also presented at LPSC involving the Human Crewed Interplanetary Transport Architecture (HUCITAR), which is a mission concept designed to send humans to Mars and the dwarf planet Ceres.

For this research, the team examined several ways how the Lunar Gateway could be used to help test and prepare technologies and astronauts for future human missions to Mars and Ceres between 2040 and 2050, including propulsion and refueling, life support and radiation shielding, assembly and maintenance, and communications and navigation.

Additionally, they proposed a mission plan for sending humans to Mars and Ceres after launching from the Lunar Gateway, which would involve traveling to Mars, conducting orbital and surface operations, traveling to Ceres for the same goals, then returning home. While the researchers emphasize confidence in their goals and objectives, they caution of the challenges, including risk management, logistical and financial support, science priorities, and technology advancements.

The study concludes, “Advancing the Lunar Gateway to support multi-planetary missions to Mars and Ceres represents a bold step forward in human space exploration. This approach optimizes resources by combining multiple destinations into a single mission and creates sustainable infrastructure for ongoing deep space exploration. Realizing such ambitious missions by 2040-2050 will require global cooperation, sustained funding, and significant technological advancements.”

This study comes as an international consortium comprised of NASA, the European Space Agency (ESA), the Japan Aerospace Exploration Agency (JAXA), the Canadian Space Agency (CSA), and the Mohammed Bin Rashid Space Centre (MBRSC) are currently constructing the first modules of Lunar Gateway with a planned launch date of 2027. These first modules are the Power and Propulsion Element (PPE) and Habitation and Logistics Outpost (HALO), which are being manufactured by Maxar Technologies and Thales Alenia Space, respectively. While this first launch will be uncrewed, the four subsequent missions delivering additional modules will be crewed as part of Artemis IV, V, VI, and VII and currently scheduled for September 2028, March 2030, March 2031, and March 2032, respectively. Expected science to be conducted on the Lunar Gateway includes the fields of planetary science, human health, solar physics, and Earth observation, just to name a few.

Lunar Gateway holds the potential to build on the fantastic research and science that has been conducted on the International Space Station (ISS) for over two decades, which has been instrumental in advancing our understanding of how humans can live and work in space and various scientific fields, including those listed above. While the ISS has been limited to conducting research in low Earth orbit, Lunar Gateway could serve as a springboard for humans exploring beyond the Moon while developing the technology and architecture for mission success.

How will Lunar Gateway help advance human space exploration in the coming years and decades? Only time will tell, and this is why we science!

• As always, keep doing science & keep looking up!

You'd think that icy worlds are frozen in time and space because they're - well - icy. However, planetary scientists know that all worlds can and do change, no matter how long it takes. That's true for Europa, one of Jupiter's four largest moons. Recent observations made by the James Webb Space Telescope (JWST) zero in on the Europan surface ices and show they're constantly changing.

Dr. Ujjwal Raut of the Southwest Research Institute (SWRI) reported on the changes reflected in the JWST studies. Not only does Europa's surface have amorphous ice, but there's evidence of crystalline ice scattered around there. That indicates the presence of an active water source, such as the subsurface ocean. It also points toward geologic processes that affect the surface. The changes seen at Europa are very short-term, perhaps two weeks in some places.

“Our data showed strong indications that what we are seeing must be sourced from the interior, perhaps from a subsurface ocean nearly 20 miles (30 kilometers) beneath Europa’s thick icy shell,” said Raut. “This region of fractured surface materials could point to geologic processes pushing subsurface materials up from below. When we see evidence of CO₂ at the surface, we think it must have come from an ocean below the surface. The evidence for a liquid ocean underneath Europa’s icy shell is mounting, which makes this so exciting as we continue to learn more.”

What Happens to Europa

As a Galilean moon, Europa orbits near the planet and within its strong magnetic field. Thus, the surface gets bombarded by radiation. It is tidally locked, meaning it shows the same face to Jupiter as it orbits. Europa has a rocky and metallic interior, covered by an ocean and topped by an icy shell that's fairly young in geological terms. It appears to be no more than 180 million years old. That tells us it has been resurfaced from within. JWST's spectral studies of the surface show that the ice crystallizes in different ways in various places. Generally, water ice freezes into hexagonal crystals. That's what we see on Earth when it snows or when rain freezes. However, Earth's surface is largely protected from outside influences such as radiation and the ice stays in crystalline form much longer.

The JWST shows that ice on Europa is developing at different rates in different places, such as Tara Regio, where crystalline ice (lighter colors) is found on the surface as well as below the surface.

Courtesy SWRI.

On Europa, charged particles trapped in Jupiter's magnetic field bombard the surface. That disrupts the crystalline structure of the ice, turning it into amorphous ice. If that's all that ever happened to Europa's surface, you'd expect to see amorphous ice everywhere. Instead, the JWST spectral studies showed evidence of crystalline ice. There are also other surface "units", such as ridges and cracks. Radiation doesn't explain them, but other processes can create them. Combined with the new data collected by JWST, Raut said they are seeing increasing evidence for a liquid ocean beneath the icy surface.

Resurfacing Europa

Scientists thought that Europa’s surface was covered by a very thin (perhaps half a meter thick) layer of amorphous ice protecting crystalline ice below. The new evidence of crystalline ice on the surface also shows up in other areas, especially an area known as the Tara Regio. According to co-author Richard Cartwright of the Johns Hopkins Applied Physics Laboratory, the surface may be different than expected in places. “We think that the surface is fairly porous and warm enough in some areas to allow the ice to recrystallize rapidly,” said Cartwright. “Also, in this same region, generally referred to as a chaos region, we see a lot of other unusual things, including the best evidence for sodium chloride, like table salt, probably originating from its interior ocean. We also see some of the strongest evidence for CO₂ and hydrogen peroxide on Europa. The chemistry in this location is really strange and exciting.”

The CO₂ found in this area includes the most common type of carbon, with an atomic mass of 12 and containing six protons and six neutrons, as well as the rarer, heavier isotope that has an atomic mass of 13 with six protons and seven neutrons. That raises questions about the origin of the CO₂. "It is hard to explain, but every road leads back to an internal origin, which is in line with other hypotheses about the origin of ¹²CO₂ detected in Tara Regio,” Cartwright said.

Sources of Water and Resurfacing

So, how is water forced to the surface? There are two main sources of heat at work: tidal heating and radioactive decay at the core. Both of these processes warm the subsurface ocean and force water to the surface. What causes the chaotic terrain seen at Europa in such places as Tara Regio? There are several possible ways. One way is through the formation of chaos regions - those places that appear to be cracked and jumbled. They could be the result of material forcing its way via diapirs (think of them as stovepipes from below that convey warmer water and slush up to the surface). Once that water gets to the surface, it freezes rapidly into the crystalline ice JWST detected. The water also brings up dissolved CO₂ and other materials.

A geological map of Europa showing its interior structure and processes that help change the surface.

Courtesy: by David Hinkle (JPL) in Roberts, J.H., McKinnon, W.B., Elder, C.M. et al. Exploring the Interior of Europa with the Europa Clipper.  CC BY 4.0

Another method for water delivery to the surface is through plumes. These geysers shower the surface with ice grains. Other mechanisms that could be forming crystalline ice are migration from other parts of the surface and impact exposure. Impacts are well known to "garden out" fresh ice in a short period of time. Such a collision may well explain the ice seen at Tara.

This resurfacing with crystalline ice is relatively short-lived. That's because the constant bombardment of charged particles works immediately to create amorphous ice. The authors of the paper (see below) state that the charged particle-driven process that changes the ice may work in as little as 15 days on Europa's leading hemisphere. In other places, that might work faster. So, given that Europa is constantly refreshing its surface and charged particles are rapidly breaking that ice down, Europa is a busy, constantly changing place. The upcoming Europa Clipper mission should be able to study these regions in more detail during its many close passes of this tiny moon.

For More Information

• SwRI Scientists Contribute to Uncovering Ongoing Surface Modification on Jupiter's Moon Europa
• JWST Reveals Spectral Tracers of Recent Surface Modification on Europa

The Mars Reconnaissance Orbiter (MRO), launched by NASA in 2005, is orbiting Mars tasked with studying its atmosphere, surface, and subsurface in unprecedented detail. Equipped with a suite of advanced instruments—including high-resolution cameras, spectrometers, and the SHAllow RADar (SHARAD) MRO has revolutionised our understanding of Martian geology, climate history, and potential water reservoirs beneath the surface. Beyond science, it also plays a vital role in relaying data from other Mars missions back to Earth.

Artist's concept of NASA's Mars Reconnaissance Orbiter

(Credit : NASA/JPL/Corby Waste)

SHARAD is perhaps one of its most powerful tools designed to probe beneath the surface and reveal features. However, SHARAD’s placement on the side of the spacecraft—opposite the imaging payload has since it began operations, limited its effectiveness. To compensate, MRO has routinely executed roll manoeuvres of up to 28°, slightly tilting the spacecraft to boost the signal-to-noise ratio (S/N) of radar echoes returned from below the surface.

Now, thanks to new modelling efforts, MRO is taking a bold leap forward. Recent simulations by a team led by Nathaniel E. Putzig from the Planetary Science Institute suggested that dramatically increasing the roll angle up to 120°, could improve SHARAD’s signal clarity by approximately 10 decibels compared to standard nadir-pointing observations. Acting on this prediction, mission controllers initiated a limited series of “very large roll" (VLR) experiments to test the impact of these extreme manoeuvres on radar performance.

Since May 2023, three such VLR manoeuvres and observations have been conducted, and the results have exceeded expectations. The signal to noise ratio improved significantly by 9, 11, and 14 dB in the respective passes allowing SHARAD to detect features at depths never before seen. In the low-dielectric Medusae Fossae region, radar signals penetrated as deep as 800 meters, while in the icy terrains of Ultimi Scopuli, echoes reached depths of 1,500 meters. In both cases, researchers were able to identify basal layers critical markers for understanding Mars's geological and climatic history. The second VLR pass also revealed enhanced reflections throughout the entire ice column, offering fresh insights into the internal structure of the Martian polar ice.

Image of Medusae Fossae on Mars

(Credit : NASA)

Even in the more challenging high dielectric terrain of Amazonis Planitia, the third VLR manoeuvre brought improved continuity of a known subsurface interface, although it did not reveal any deeper layers. Encouraged by these successes, the MRO mission team plans to conduct additional VLR observations across Mars's polar regions, midlatitude glaciers, and other areas rich in ice, sediment, and volcanic deposits.

With this bold new approach, MRO continues to push the boundaries of planetary science literally rolling over to unlock Mars’s deepest secrets.

Source : 

• SHARAD Illuminates Deeper Martian Subsurface Structures with a Boost from Very Large Rolls of the MRO Spacecraft

How can fission-powered propulsion help advance deep space exploration, specifically to the outer planets like Jupiter, Saturn, Uranus, and Neptune? This is what a recent study presented at the 56^th Lunar and Planetary Science Conference (LPSC) hopes to address as a pair of researchers from India investigated the financial, logistical, and reliability of using fission power for future deep space missions. This study has the potential to help scientists, engineers, and future astronauts develop next-generation technologies as humanity continues to expand its presence in space.

Here, Universe Today discusses this incredible research with Malaya Kumar Biswal, who is the Founder & CEO of Acceleron Aerospace in Bangalore, India, regarding the motivation behind the study, significant takeaways, and exploring other star systems. Therefore, what was the motivation behind the study?

“The primary motivation for this study was the growing realization that our current propulsion and power systems—particularly chemical and solar-based—are not sufficient for long-duration or deep space missions,” Biswal tells Universe Today. “As we push the boundaries of exploration toward Mars, the outer planets, and even interstellar space, we need power systems that are not only reliable but also capable of delivering sustained energy for decades. Nuclear power, especially fission-based systems, offers a solution with its high energy density and independence from sunlight. Our aim was to explore how these technologies could transform the way we plan, power, and execute missions beyond Earth orbit enabling true multiplanetary and interstellar missions.”

For the study, the researchers evaluated a myriad of characteristics regarding how fission-powered propulsion systems could successfully advance deep space exploration, including power systems, key advantages, notable developments, potential applications, and limitations. This involved in-depth analyses into radioisotope electric propulsion, fission electric propulsion, high-power output and needs, long-duration missions, NASA’s KRUSTY (Kilowatt Reactor Using Stirling Technology) proposed concept, multiplanet exploration, Moon and Mars crewed missions, and comparing to traditional systems.

In the end, the researchers referred to fission power propulsion as a “game-changer” offering a myriad of benefits and advances beyond current propulsion technologies with very few limitations, specifically radiation shielding and mass. But what are the most significant takeaways from this study?

Biswal tells Universe Today, “First, fission power systems offer significantly higher and more consistent power output than traditional sources, which is critical for both propulsion and life-support systems on long missions. Second, these systems can reduce transit time, support larger payloads, and operate in environments where solar power simply isn’t viable—such as deep space or shadowed planetary surfaces. Third, while the technology shows incredible promise, it also comes with challenges, particularly in radiation shielding, safety protocols, and system mass. However, ongoing developments like NASA’s Kilopower project show that we’re moving steadily toward making this a practical reality.”

The researchers discuss in-depth how fission propulsion could be used to explore the entire solar system, all the way out to the Kuiper Belt, which begins at the inner orbit of Neptune at approximately 30 astronomical units (AU) and extends as far as 50 AU, with 1 AU being the distance from the Sun to the Earth. For context, the AU distance to Mercury, Venus, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto are 0.39, 0.72, 1.52, 5.20, 9.54, 19.22, and 30.06, and 39.5, respectively.

The researchers note these travel distances are possible due to fission propulsion being able to function for decades, opening doors to expanding humanity’s presence well beyond Earth, possibly to the moons of the giant planets. While this study doesn’t mention traveling beyond the solar system and into interstellar space, other studies have proposed sending spacecraft to our nearest star, Proxima Centauri. Therefore, could nuclear-powered propulsion be used to explore other star systems, specifically Proxima Centauri?

Biswal tells Universe Today, “Exploring another star system like Proxima Centauri is a monumental challenge, but nuclear propulsion is one of the few technologies that could make it conceivable within this century. Although reaching Proxima Centauri, which is over 4 light-years away, would still require travel times of several decades to centuries with current technology, nuclear-powered propulsion—especially when combined with electric or ion propulsion systems—could drastically improve our reach and reduce mission duration compared to conventional methods.”

Biswal continues, “For such interstellar missions, high-thrust nuclear thermal propulsion could be used to exit the solar system efficiently, followed by long-duration electric propulsion powered by nuclear reactors to maintain velocity. In theory, these systems could enable probe missions that might one day send back data from nearby exoplanets. While we’re not there yet, this study forms part of the groundwork needed to seriously consider such possibilities in the future.”

This study comes as these same researchers also presented a study at the 56^th LPSC proposing the use of a Human-Crewed Interplanetary Transport Architecture (HUCITAR) for exploring Mars and the dwarf planet Ceres, which is also the largest planetary body on the Main Asteroid Belt with evidence that it once contained a subsurface salty liquid water ocean. This HUCITAR study builds on a 2021 study and 2022 study they presented at the AIAA SciTech Forum that also discussed human exploration of Mars and Ceres. As humanity continues to expand beyond Earth and into the cosmos, these studies could provide the framework for future exploration initiatives, enabling humans to reach distant worlds and establish permanent settlements both within and beyond the solar system in just a few generations.

Biswal tells Universe Today, “Our proposed architecture makes a strong case for Nuclear Electric Propulsion (NEP) and Nuclear Thermal Propulsion (NTP) as essential enablers of reduced transit time, increased payload capacity, and mission redundancy. In addition to propulsion, our studies examine mission design in detail, including trajectory optimization, cost models, safety protocols, power generation using RTGs [Radioisotope thermoelectric generator] and fission reactors, and astronaut health considerations for long-duration exposure.”

Biswal continues, “If there's one key message we want to leave with readers, it's that nuclear-powered systems are not just a distant dream—they are rapidly becoming a necessity for meaningful exploration beyond low Earth orbit. At Acceleron Aerospace, we're committed to providing the foundational research, technologies, and mission concepts needed to make this vision achievable, starting with Mars and Ceres, and eventually extending to the outer solar system.”

How will fission-powered propulsion help advance deep space missions in the coming years and decades? Only time will tell, and this is why we science!

• As always, keep doing science & keep looking up!

Just when astronomers think they're starting to understand stellar activity, something strange grabs their attention. That's the case with a newly discovered stellar object called ASKAP J1832-0911. It lies about 15,000 light-years from Earth and belongs to a class of stellar objects called "long-period radio transients." That means it emits radio waves that vary in their intensity on a schedule of only 44 minutes per cycle. It does the same thing in X-ray intensities, which is the first time anybody's seen such a thing coupled with long-period radio transits.

Why does it vary in both radio and X-rays like that? Figuring that mystery out is the job of Dr. Ziteng Wang of Curtin University in Australia and a team of astronomers. “Astronomers have looked at countless stars with all kinds of telescopes and we’ve never seen one that acts this way,” said Wang. “It’s thrilling to see a new type of behavior for stars.”

However, ASKAP J1832 (for short) exhibits even weirder behavior. Using Chandra and the SKA Pathfinder, the team found that it also dropped off in X-rays and radio waves dramatically over six months. So, what's going on there?

A close-up image of ASKAP J1832 in X-ray and radio light.

Credit: X-ray: NASA/CXC/ICRAR, Curtin Univ./Z. Wang et al.; Radio: SARAO/MeerKAT; Image processing: NASA/CXC/SAO/N. Wolk

What's Causing ASKAP J1832's Emissions?

The big questions about this weird object center around what it is and whether its behavior gives clues to its origin story. Is it typical of long-period radio transients? “We looked at several different possibilities involving neutron stars and white dwarfs, either in isolation or with companion stars,” said Dr. Nanda Rea of the Institute of Space Sciences in Barcelona, Spain. “So far, nothing exactly matches up, but some ideas work better than others.”

The science team is examining a few possibilities, but isn't completely sure that a pulsar or a neutron star is at the heart of ASKAP J1832. A pulsar does have varying intensity in its emissions. That's because it's a stellar remnant, left over from a catastrophic event called a supernova explosion that marks the death of a massive star. The core of the star is all that's left, and it's spinning very rapidly. It gives off radiation, which appears as a pulsating signal as the object spins many times per second.

A neutron star, which is also the leftovers from a supernova explosion, isn't a good explanation either. When such an object exists with a partner star, its gravity will suck material away from the partner star. That action causes variation in emission intensities, too. However, the research team doesn't think that such a pair explains ASKAP J1832 because the intensities in the radio and X-ray emissions don't match what these objects typically give off.

The team also doesn't think it's a magnetar, which is a neutron star with an intensely strong magnetic field. Magnetars are typically pretty old, and some of the signals from ASKAP J1832 aren't typical of those, either. The only other possibility might be a white dwarf with a companion star. Such binaries do often give off strong radio and X-ray emissions that could fit the description of what Chandra and the SKA instruments saw. However, to make that work, the white dwarf would need an incredibly strong magnetic field - something that astronomers haven't yet seen.

ASKAP J1832 does appear in the same field of view as a supernova remnant. It's not likely to be associated, though, and is probably just a case of coincidental location.

So, What Is It?

Ultimately, the scientists have not figured out what's causing ASKAP J1832 to feature such changes in its emission intensities. It could be an entirely new version of the objects they've already considered. More observations are needed to pin it down.

Beyond observations with Chandra and SKA, this region of space has also been studied by the SWIFT, the Very Large Array, the Australia Telescope Compact Array, the Giant Metrewave Radio Telescope, MeerKAT, and other facilities. Each of these observations has seen the intensity variations and helped establish baseline timings for the outbursts. For the moment, however, astronomers are still trying to fit what they've seen into models that will help them assign an origin and explanation for the emissions.

“We will continue to hunt for clues about what is happening with this object, and we’ll look for similar objects,” said team member Dr. Tong Bao of the Italian National Institute for Astrophysics (INAF) – Osservatorio Astronomico di Brera in Italy. “Finding a mystery like this isn’t frustrating — it’s what makes science exciting!”

For More Information

• Eccentric 'Star' Defies Easy Explanation, NASA's Chandra Finds
• Detection of X-ray Emission from a Bright Long-period Radio Transient