SPACE/COSMOS
How space weather shapes young planets
image:
Adina Feinstein
view moreCredit: Paul Henderson
Scientists suspect powerful solar flares helped strip away the atmospheres of planets like Mars. A Michigan State University researcher is now searching for evidence of how those same forces shape planets beyond our solar system.
Adina Feinstein, assistant professor of physics and astronomy, believes exoplanets are the key to understanding the early days of our solar system. This week, she received a Schmidt Sciences FirstLight grant to investigate how space weather influences young planets.
The five year, $500,000 per year grant is part of a larger effort by Schmidt Sciences to boost scientific discovery through a new fleet of coordinated observatories, known as the Schmidt Observatory System. Over the next few years, the organization plans to build three ground-based facilities and one space telescope to advance astronomical research. While government-funded telescopes and observatories can take decades to develop, Schmidt Sciences hopes to shorten that timeline.
With the help of the grant, Feinstein will use these facilities to monitor outbursts from young stars and search for evidence that the planets orbiting them are losing their atmospheres.
“Having Schmidt Sciences build these distinct facilities for the community and provide the financial support to develop software analysis tools and preparatory science for them is career-making,” Feinstein said.
Young stars, wild weather
The sun we know today was once wilder and less predictable billions of years ago. Scientists believe young stars experience more frequent and powerful outbursts than older stars like our sun, potentially stripping away parts of the atmospheres of nearby planets.
Today, young stars beyond our solar system are still in their rebellious phase, unleashing powerful flares that could wreak havoc on Earth's electrical grid if they occurred close to home. The young exoplanets that revolve around these stars may be especially vulnerable, with their atmospheres at risk of losing substantial amounts of gas.
“We’re trying to tie distinct observations together to see how space weather affects the entire evolutionary path of these planets,” Feinstein said.
Solar flares happen when magnetic field lines around a star become twisted and release enormous amounts of energy. Some stellar outbursts also eject charged particles into space. When that energy and material reaches a planet, they can heat and alter its atmosphere, allowing some particles, like hydrogen and helium, to escape into space while triggering chemical reactions that form new molecules.
“It’s a huge source of energy that can change whatever is going on in the atmosphere at any given time,” Feinstein said. “That atmosphere might go back to what it looked like before and equilibrate, but it may not always do that.”
Searching for clues in starlight
Feinstein hopes to connect the dots between what young stars are doing and how their planets respond.
The new observatories will allow her team to monitor thousands of stars for flares and other outbursts, using optical and radio observations to build a clearer picture of space weather around young planetary systems.
The team will also repeatedly observe young exoplanets, searching for changes in how quickly their atmospheres are escaping into space. By comparing those measurements with activity on the planets’ host stars, researchers hope to determine whether powerful outbursts are responsible for atmospheric loss.
To find evidence of this effect, Feinstein relies on observing the moment a planet passes in front of its star, known as a transit. When starlight passes through a planet’s atmosphere, astronomers can split that light into different wavelengths. By observing planetary transits at wavelengths sensitive to hydrogen and helium, Feinstein and her team will measure how much gas is being lost and how the lost gas is structured. In extreme cases, a planet may have a cometary tail-like structure of an escaping atmosphere trailing behind it.
The five-year grant will support an international team of researchers, including graduate students and postdoctoral scholars, as they prepare to use the new facilities and eventually conduct the survey.
Exoplanets offer a glimpse of our solar system’s earliest days, Feinstein said. By studying planets of different ages, researchers can better understand how planets evolve and why some planets in our solar system have thick atmospheres while others have almost none.
“This research allows us to piece together what might have happened in the early solar system and understand why planets look the way they do today,” Feinstein said.
Hidden in plain sight in Ryugu and meteorites
image:
Schematic views of previous interpretation and proposed model of aqueously altered Ryugu and carbonaceous meteorites.
view moreCredit: Keisuke FUKUSHI, Kanazawa University (2026)
Asteroid Ryugu and some carbonaceous meteorites, which are thought to have similar origins in the early Solar System, are known as chemically “primitive” materials because they preserve the chemical composition of the early Solar System remarkably well. Yet these rocks also reacted extensively with water after they formed, transforming many of their original minerals into new ones. When rocks react with water, elements can dissolve into the fluid or move from one place to another, potentially altering the original chemical composition. This seemingly contradictory combination — extensive reaction with water while preserving the chemical composition of the early Solar System — has long been one of the puzzles of cosmochemistry.
A research team led by Kanazawa University and The University of Tokyo used powerful X-rays at the large-scale synchrotron facilities KEK-PF and SPring-8 to examine these extraterrestrial materials in detail. They identified a previously overlooked material that may provide an important clue to this long-standing puzzle.
In the conventional mineralogical picture, aqueous alteration of primitive carbonaceous meteorites has been interpreted mainly in terms of the formation of serpentine and saponite. Using synchrotron-based soft X-ray absorption spectroscopy, however, the researchers found that, in addition to the well-recognized serpentine and saponite, a previously under-recognized component resembling poorly crystalline magnesium silicate hydrate (M-S-H) is widespread in Ryugu and carbonaceous meteorites.
“What makes M-S-H particularly interesting is that it can accommodate a wide range of magnesium-to-silicon ratios,” says Keisuke Fukushi of Kanazawa University. “This flexibility may be key to understanding how water-rock interactions proceeded without erasing pre-existing chemical differences within their parent asteroids.”
In general, materials with different compositions tend to be stable under different aqueous conditions. However, laboratory experiments combined with previously published data on the solubility of M-S-H showed that M-S-H with different magnesium-to-silicon ratios can exist under similar aqueous conditions. The serpentine and saponite observed in the samples may also have formed from precursor M-S-H with corresponding compositions before transforming into these more crystalline minerals.
Together, these results suggest a pathway by which different alteration minerals could form while preserving pre-existing compositional differences from place to place. M-S-H may therefore provide an important clue to understanding how these materials could be extensively altered yet remain chemically primitive.
Funding
This work was supported by Grants-in-Aid for Scientific Research from the Japan Society for the Promotion of Science (JSPS; grant numbers JP22H04900, JP24H00268, JP26K22374, JP26H00438, and JP26K21720) and the Program for Forming Japan's Peak Research Universities (J-PEAKS) Grant Number JPJS00420230006.
Journal
Communications Earth & Environment
Article Title
Pervasive poorly crystalline Mg-rich hydrous silicate material in C-type asteroid matrices
Hidden planet emerges from the glare
New technique cuts through starlight to find giant exoplanet lost in JWST data
image:
Left: JWST/NIRCam observation of star 51 Eridani A (51 Eri) in the F430M filter, using standard method KLIP (Soummer et al. 2012) to subtract the glare of the star. This method was not able to detect the planet 51 Eri b in the original analysis (Balmer et al. 2025), whose expected location is marked with a dashed circle. Middle: The same observation, but using new method FLIP (Ferrer-Chavez et al. 2026) to subtract the glare of the star. Astrophysicists obtained a significant detection (>5 sigma) of 51 Eri b. Right: Simulated image of 51 Eri b, highlighting that the planet is detected at its expected location and that the planet signal has the expected morphology. The location of the star 51 Eri is marked with a star symbol.
view moreCredit: Visualization credit: Rodrigo Ferrer-Chavez
Even the world’s most powerful telescopes have their blind spots.
Although NASA’s James Webb Space Telescope (JWST) can peer billions of years into the past, it still struggles to photograph planets orbiting nearby stars. Stars shine with such extraordinary brightness that their glare overwhelms nearby planets’ faint glow.
Now, a Northwestern University-led team of astrophysicists has developed a new computational technique that cuts through the glare — revealing planets previously hidden from view.
By combining physics-based modeling with machine-learning techniques, the new method accounts for tiny imperfections in the telescope that interfere with its ability to detect faint objects. When the team applied their method to existing JWST observations, they improved the telescope’s sensitivity by up to 15 times. After the new method erased glare, it revealed a giant exoplanet in an image where conventional processing simply could not see it.
The advance could enable astronomers to discover smaller, colder and fainter planets without changing the telescopes themselves.
The study will be published on Wednesday (Nov. 4) in the journal Nature.
“Planets are a million times fainter than their stars,” said Northwestern’s Rodrigo Ferrer-Chavez, who led the study. “So, to image exoplanets, we need to remove that glare. That is a very tricky problem because even the tiniest changes in the telescope can affect how that glare appears. Slight shifts or tilts — even on the scale of just a few nanometers — can change the pattern of light. Our method models how light travels through the telescope and accounts for those tiny changes, allowing us to remove the glare much more precisely.”
Ferrer-Chavez is a Ph.D. student in astronomy at Northwestern’s Weinberg College of Arts and Sciences, where he is a member of Jason Wang’s research group. Wang is an assistant professor of physics and astronomy at Weinberg and co-author of the study. Wang and Ferrer-Chavez are members of the Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA).
Hidden in a sea of starlight
Photographing a planet outside of our solar system is a bit like trying to spot a firefly hovering next to a blazing floodlight. Even relatively bright young giant planets can be 100,000 times fainter than their host stars.
To tackle this challenge, telescopes like JWST use specialized instruments called coronagraphs, which block out starlight to detect faint objects. But blocking the star isn’t enough. Some starlight still seeps through, producing a hazy pattern that can obscure planets. So, astronomers then use image-processing techniques to remove the remaining glare.
“For the past 20 years, astronomers have tackled this problem by observing a different star and using its image as a reference,” Wang said. “Then, they subtract that reference image from the original observation to remove the unwanted glare to reveal faint planets that otherwise might be hidden.”
Taking the wobble out of the picture
The problem is no telescope can stay perfectly still. Nearly imperceptible changes in the telescope’s physical structure alter patterns of scattered starlight. As a result, the reference image never perfectly matches the actual observation. Even the slightest mismatch can leave behind just enough glare to hide a faint planet.
“We try to make telescopes extremely stable, but there are extreme engineering challenges that we haven’t quite solved yet,” Wang said. “There are known causes of instability and unknown causes. Small thermal changes could cause a mirror to expand or contract by a picometer. Telescopes like JWST have cryocoolers to keep the instrument super cold. Those coolers have little motors that can cause the mirrors to vibrate. So, there are issues like those but also issues that we still don’t understand as we learn how to build these complex telescopes.”
Instead of relying on reference photographs alone, the Northwestern team took a different approach. Their new method, called Physics-based Learning for Imaging Planets (FLIP), creates a “digital twin” of the telescope — a virtual replica that simulates how starlight travels through the telescope’s mirrors and reaches its detectors.
Using computational techniques similar to those used to train AI models, the team fine-tuned millions of parameters in the digital twin to account for tiny imperfections in the telescope, including subtle shifts in position and distortions in its optics. Rather than using AI to identify planets, the researchers combined their knowledge of the telescope’s physics with powerful optimization tools.
“We used the same computational tools that researchers use to train AI models, but we did not actually use AI,” Wang said. “Because we already know the physics, we don’t need AI to understand what’s happening.”
By repeatedly adjusting the digital twin until it closely matched the telescope’s actual observation, FLIP recreated the unwanted starlight with remarkable precision. The researchers then subtracted that simulated glare from the image.
Revealing a previously hidden planet
To test their approach, the researchers reanalyzed past observations from JWST. They examined observations of two stars — HIP 65426 and 51 Eridani — with known planets as well as a third star, TYC 5899, with no known planetary companions.
Across the observations, FLIP consistently outperformed conventional image-processing techniques, improving sensitivity for detecting faint planets by 2 to 15 times. With the increased sensitivity, the team detected 51 Eridani b, a previously discovered giant planet beyond our solar system hidden in two-year-old JWST data. Carbon dioxide in the planet’s atmosphere absorbed light in the infrared wavelength that JWST observes, making the planet’s signal even fainter.
Although astronomers previously discovered 51 Eridani b with ground-based telescopes, conventional image processing could not distinguish it from residual glare at the wavelength JWST uses to study carbon dioxide in planetary atmospheres. When Ferrer-Chavez applied FLIP to the same observations, the planet emerged.
“We showed that we can actually recover a planet that people previously couldn’t see,” Wang said. “This is real data in a real scenario. It was science left on the table because we didn’t have the right tools to analyze the data in the most optimal way.”
The same property that makes a planet harder to detect also can make it more interesting to study. JWST can make sensitive observations at 4.3 microns, where carbon dioxide strongly absorbs infrared light. Detecting features at this wavelength potentially could give astronomers new clues into a planet’s atmosphere and composition.
From giant planets to Earth-like worlds
For now, Ferrer-Chavez and Wang hope FLIP will help astronomers uncover planets previously hidden within existing observations. By removing starlight more precisely, the method also could allow scientists to study planets at different wavelengths to reveal new clues about their atmospheres.
Looking further ahead, FLIP could help shape the next generation of planet-hunting telescopes. NASA’s proposed Habitable Worlds Observatory aims to directly photograph Earth-like planets orbiting distant sun-like stars. To find such small planets, the telescope may need to maintain optical stability at the picometer scale. That’s equivalent to trillionths of a meter or roughly 100 to 1,000 times more stable than JWST.
FLIP offers a potentially different path forward. Rather than relying on engineering solutions to keep a telescope perfectly stable, astronomers might be able to correct for its tiny imperfections.
“We know of no planets around other stars that are like those in our own solar system,” Ferrer-Chavez said. “It’s not that they don’t exist. It’s that we cannot see them. Every time we improve our techniques, we discover new types of planets. By finding more planets, we can better understand how planetary systems form and evolve, and ultimately how typical our own solar system truly is.”
The study, “Imaging exoplanets below the telescope stability limit,” was supported by the Space Telescope Science Institute (award number JWST-AR-07942), the Sloan Foundation (award number FG-2025-24976) and the National Science Foundation (award number PHY-2525568).
Starlight reduction visualization [VIDEO]
Stars shine with such extraordinary brightness that their glare overwhelms nearby planets’ faint glow.
Now, a Northwestern University-led team of astrophysicists has developed a new computational technique that cuts through the glare — revealing planets previously hidden from view.
This visualization demonstrates the image processing method, called FLIP, as it subtracts starlight from a James Webb Space Telescope (JWST) observation of star 51 Eridani A (51 Eri) in the F430M filter. Starlight subtraction proceeds with the iteration number shown in the lower left, eventually revealing the faint planet 51 Eri b at its expected location.
Credit
Visualization credit: Rodrigo Ferrer-Chavez
Journal
Nature
Article Title
Imaging exoplanets below the telescope stability limit
Article Publication Date
4-Nov-2026
UW scientists build whole-Earth simulation to help find life on other planets
image:
An artist’s rendition of an imagined rocky exoplanet with an atmosphere. In a new study, University of Washington researchers built a virtual Earth that realistically models the exchange of chemicals between the core, mantle, crust, surface and atmosphere. The model can help astronomers study real exoplanets and determine whether their atmospheres show evidence of alien life.
view moreCredit: 852278-MCS via Wikimedia Commons
It’s a dizzyingly busy time for scientists searching for life on distant planets. To date, astronomers have cataloged more than 6,000 planets beyond our solar system and are searching the atmospheres of the most promising worlds for chemicals that might be byproducts of life. Astrobiologists are particularly interested in atmospheres like Earth’s that trap enough heat to support liquid water on the planet’s surface, which scientists consider the key factor in determining whether a planet can support life as we know it.
But scientists also want to distinguish between habitable and inhabited worlds. To do that, they need to know what sorts of atmospheric conditions on a planet can be explained without life, so that they can identify planets with atmospheres that can only be explained by life’s influence.
To provide that planetary baseline, University of Washington researchers built a complex virtual Earth with one crucial tweak: no life.
In a paper published Sept. 18 in The Planetary Science Journal, the researchers simulated the Earth’s geochemical systems for 5 billion years — from its formation 4.5 billion years ago through roughly 500 million years in the future. The simulation modeled the exchange of chemicals between the core, mantle, crust, surface and atmosphere over time. It accurately predicted 19 planetary properties like heat flow through the mantle, but left out the influence of life on those systems. The simulation can be generalized to predict how an atmosphere might evolve on any rocky planet, and can help pinpoint evidence of life in atmospheres that don’t fit the model.
“This model can help us see how habitable but non-living planets might mimic living planets,” said lead author Samantha Gilbert-Janizek, who completed this research as a UW doctoral student of astronomy and is now a postdoctoral fellow at UC Riverside. “When we interpret observations of an exoplanet's atmosphere, this tool will help us determine the probability that what we observe indicates life on the surface.”
Gilbert-Janizek’s work builds on a model developed in the lab of senior author Rory Barnes, a UW associate professor of astronomy. Earlier versions of the model simulated the core, mantle, crust and stellar radiation, but did not include the surface or atmosphere.
A planet’s atmosphere is shaped by many nonbiological factors, including heat and gases from the interior and from the planet’s star. But the atmosphere of a distant planet is also where astronomers hope to spot explicit evidence of life.
There are many ways that life might change an atmosphere: On Earth, plants and animals pump steady streams of oxygen and methane into the sky. Those two elements destroy each other when they mingle. Thus, an alien astronomer studying our planet might suspect that something alive is replenishing the supply of both gases.
That logic led human astronomer Gilbert-Janizek to add surface and atmosphere modeling to the existing Earth simulation, completing the picture of how chemicals move through all of the Earth’s systems.
The result is a model that can be tuned to study any rocky exoplanet that astrobiologists find interesting. Researchers can plug in basic details about that planet and run the simulation to see whether the model can reproduce the observed atmosphere without the influence of life. If they can’t get a match, the planet in question gets even more interesting.
“Dr. Gilbert-Janizek's work represents an exciting step toward understanding where life can exist in the universe,” Barnes said. “After more than a decade of work by many scientists, Dr. Gilbert-Janizek has finally completed a model of the Earth that simultaneously reproduces properties of Earth's core, mantle, surface and atmosphere. That calibration gives us confidence that future simulations of exoplanets will be accurate.”
Gilbert-Janizek says the new and improved model can also help inform the design of future telescopes built to study distant planets, like the proposed Habitable Worlds Observatory.
“Realizing the ambitious goals of a telescope like the Habitable Worlds Observatory requires decades of work across many generations of scientists,” Gilbert-Janizek said. “I’m so grateful to join this lineage and one day pass the torch to the next generation so that we can continue chipping away at this question of whether or not we are alone in the universe.”
Other UW co-authors include former astronomy doctoral students Jessica Birky, now a postdoctoral researcher at the University of Oklahoma and Rodolfo Garcia, now a high school teacher in the Seattle area.
A complete list of co-authors is included with the study.
This research was funded by NASA.
For more information, contact Gilbert-Janizek at sgilbert@ucr.edu or Barnes at rory@astro.washington.edu.
Journal
The Planetary Science Journal
Article Title
A Whole-planet Model of the Earth without Life for Terrestrial Exoplanet Studies
A cosmic ‘leaf blower’: light-propelled winds help explain early universe’s bright galaxies
New simulations show that intense ultraviolet light acted like a cosmic leaf blower, pushing gas and dust away from stars in the early universe and making their galaxies appear brighter
Simons Foundation
image:
Artist’s illustration of gas being cleared from the surroundings of a star-forming region in the early universe.
view moreCredit: Matt Twombly for Simons Foundation
When astronomers looked at photos of the early universe taken by the James Webb Space Telescope, they found something odd: an overabundance of bright galaxies. Based on what they knew about the early universe, such galaxies should have been far less common in the few hundred million years following the Big Bang.
Now, using cutting-edge simulations, researchers at the Simons Foundation’s Flatiron Institute in New York City and the University of Texas at Dallas have an answer to this mystery: Powerful ultraviolet radiation produced by clusters of young stars acted like a leaf blower, flinging light-blocking gas and dust out of the galaxy and thereby making the galaxies appear brighter.
The researchers report their findings on this ultraviolet light, called Lyman-alpha radiation, November 4 in The Astrophysical Journal.
“Our results show Lyman-alpha radiation can push low-density gas and dust away really, really fast,” says Shyam Menon, a research fellow at the Flatiron Institute’s Center for Computational Astrophysics and the study’s lead author. “It can sort of clear the ‘fog,’ allowing us to see stars in the early universe much more clearly than we would otherwise.”
Lyman-alpha radiation is created when an electron and a hydrogen atom collide or when an electron joins up with a hydrogen ion. In powerful stellar environments where Lyman-alpha radiation is abundant, the pressure from the light is thought to play a role in sculpting stellar nurseries. When the Lyman-alpha radiation hits gas or dust, the material absorbs the energy and recoils from the impact like a baseball catcher’s mitt catching a fastball. This effect launches the material outward, leaving less material available to form a star. Some astronomers wondered whether, in extreme cases, the effect could be strong enough to halt star formation.
“We’ve known for a very long time that Lyman-alpha radiation could be important because it carries a lot of force,” Menon says. “But we’ve never actually been able to estimate how important it is in a realistic environment because of how challenging it is to model.”
Lyman-alpha radiation differs from many other types of radiation in how it interacts with matter. When an atom or dust grain absorbs most kinds of light, it typically re-emits that energy at a different wavelength, making the light much less likely to be absorbed again. But when hydrogen atoms absorb Lyman-alpha radiation, they almost immediately re-emit it at the same wavelength. This means nearby hydrogen atoms can absorb the light over and over before it finally escapes. While this repeated absorption and re-emission makes Lyman-alpha a particularly powerful source of radiation pressure, it also makes it computationally challenging to simulate because each interaction must be modeled.
Instead of directly simulating this radiation recycling, Menon and his collaborator, Aaron Smith at the University of Texas at Dallas, developed a workaround. They analyzed snapshots from an existing simulation of an early-universe star-forming region to calculate the force that Lyman-alpha radiation pressure would have exerted on the region’s gas and dust.
The results showed that in dense environments, the outward pressure from Lyman-alpha radiation wasn’t strong enough to counteract gravity. While gas and dust hit by the radiation recoiled, they remained bound to the stellar nursery by gravity. This means that the radiation likely wouldn’t have strongly affected star formation in dense regions in the early universe. However, in the spaces between stars where gas was less dense and gravity was lower, the Lyman-alpha radiation was able to win against gravity.
“When the density is low enough, the Lyman-alpha radiation can push the gas to really high speeds, launching explosive winds that can shoot material clear out of the galaxy,” Menon says.
This effect likely contributes to the brightness of early galaxies. If Lyman-alpha radiation pressure is pushing away loose gas and dust from between stars, it clears the line of sight between those stars and us.
While the results are an important step toward understanding the impact of Lyman-alpha radiation, the findings are just the tip of the iceberg. More research is needed to better grasp the nature of dust in the early universe, Menon says. To fully understand the effects of Lyman-alpha radiation pressure, researchers will need simulations of the early universe that self-consistently incorporate Lyman-alpha radiation, gas flows and star formation.
Recent work by Olof Nebrin of Stockholm University and study co-author Aaron Smith of the University of Texas at Dallas has demonstrated that these effects can be modeled in two dimensions, Menon says. “But the hope is that in the coming years, with improvements to computing power and the development of more effective algorithms, we can eventually do these simulations in three dimensions.”
Journal
The Astrophysical Journal
Article Title
Lyman-alpha Radiation Pressure in Dense Star Clusters: Implications for Star Formation and Winds at Cosmic Dawn
Article Publication Date
4-Nov-2026
An infographic explaining how radiation propelled light-blocking gas and gust.
Credit
Lucy Reading-Ikkanda/Simons Foundation
Simulations [VIDEO]
Multiple views of a 2.5-million-year simulation visualizing a gas cloud as it is cleared away and the formation of stars. From left to right, the views show the gas density, ionization and temperature.
Credit
Shyam Menon (Flatiron Institute) and Aaron Smith (UT Dallas)
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