When Impacts Bring Back the Air: How Collisions Could Revive Atmospheres on M-Dwarf Worlds
Prune C. August and colleagues show that rocky planets orbiting M-dwarf stars may repeatedly lose and regain their atmospheres. When gases like CO₂ freeze on the nightside, meteorite impacts can re-vaporize them, temporarily restoring an atmosphere. Their models predict that such planets could spend up to 80% of their lifetimes with these transient atmospheres, reshaping how astronomers interpret atmospheric “non-detections.”
Peering Into TRAPPIST-1e: JWST’s First Glimpses of a Habitable-Zone Rocky World
Espinoza and collaborators used JWST to observe four transits of TRAPPIST-1 e, a rocky planet in the habitable zone. They found that stellar activity strongly contaminates the data but developed new statistical methods to handle it. Their results rule out a thick hydrogen-rich atmosphere, suggesting TRAPPIST-1 e, if it has an atmosphere, likely hosts heavier gases such as carbon dioxide.
TRAPPIST-1 d: Searching for Signs of Air on a Nearby Earth-Sized World
Astronomers used JWST to study TRAPPIST-1 d, an Earth-sized planet near the habitable zone of its star. The data revealed a flat transmission spectrum, ruling out thick atmospheres of hydrogen, methane, water vapor, or carbon dioxide. This suggests TRAPPIST-1 d is either airless, has only a very thin atmosphere, or is shrouded by high-altitude clouds, offering key insights into how rocky planets around small stars evolve.
From Clouds to Planets: Tracking Organic Molecules Through Star Formation
Pierre Marchand and collaborators used simulations to study how complex organic molecules (COMs) evolve during star formation. They found that only simple COMs like methanol and ethanol are mostly inherited from the parent cloud, while heavier molecules form later during collapse or in the disk. Abundances change with time and depend on environmental conditions, meaning the chemical makeup of forming planets is shaped by both inheritance and new formation.
Building Earth Through Cosmic Collisions: How Giant Impacts Shaped Rocky Planets
The study by Maeda and Sasaki shows that Earth-like planets form through repeated giant impacts and chemical reactions between atmospheres, magma oceans, and cores. Early impacts load protoplanets with too much hydrogen, while later collisions, after the gas disk fades, strip and rebalance this excess. This sequence produces planets with core compositions and densities similar to Earth’s, highlighting the importance of timing in planet formation.
A Thick Blanket for Early Mars: Evidence of a Massive Primordial Atmosphere
Sarah Joiret and colleagues show that Mars once had a massive primordial atmosphere, captured from the solar nebula. By modeling comet impacts and comparing expected xenon delivery with today’s measurements, they find Mars’s atmosphere must have been at least 2.9–14.5 bar. This thick hydrogen-rich blanket may have warmed early Mars and shaped its volatile history.
Mapping Jupiter’s Skies: A Full-Atmosphere Model
Antonín Knížek and colleagues built the first full-atmosphere model of Jupiter, combining deep thermochemistry with upper-atmosphere photochemistry. The model predicts a mixed ammonia–ammonium hydrosulfide cloud layer, stable nitrogen levels from quenching, and a stratospheric region where hydrogen cyanide forms at detectable levels. These results bridge gaps between earlier models and make new, testable predictions for future missions.
Hunting for Air: Testing the Cosmic Shoreline Around M Stars with JWST
The paper by Jegug Ih and collaborators uses simulations and statistical modeling to determine whether rocky planets around M stars have atmospheres. By framing target selection as an optimization problem, they test different observation strategies with JWST. Results show that a “wide and shallow” survey can efficiently limit atmospheric occurrence rates and, if a Cosmic Shoreline exists, detect it within ~500 hours.
How Titan’s Soil Controls Its Skies: Thermal Inertia and the Boundary Layer on Saturn’s Largest Moon
This study explores how Titan’s surface thermal inertia influences its near-surface atmosphere. Using simulations, Han and Lora show that daily temperature swings depend strongly on surface properties, while seasonal changes are mostly shaped by the atmosphere. Their results explain past Huygens probe data and predict stable conditions for the upcoming Dragonfly mission.
What Titan Teaches Us About Alien Atmospheres: The Detection-vs-Retrieval Challenge
This study uses Titan’s atmosphere as a test case to highlight challenges in analyzing exoplanet atmospheres. The authors show that pre-selecting molecules for retrieval can bias results, even for major gases like methane. They propose an iterative method using scale height to better identify dominant atmospheric components, offering a more reliable approach for future exoplanet studies.
A Breath of CO₂: Searching for Life-Friendly Planets through Atmospheric Clues
This study explores how future space missions like LIFE could detect trends in atmospheric CO₂ across many exoplanets to identify signs of habitability or life. Using simulations and statistical modeling, the authors show that CO₂ patterns influenced by geology—and potentially biology—can be detected in planet populations, though observational biases must be addressed for reliable results.
Hunting for Hidden Signs of Life: How Earth-like Biosignatures Challenge Astronomers
Amber Young and colleagues explored whether signs of life—specifically, chemical disequilibrium like Earth's O₂-CH₄ mix—can be detected on exoplanets. Using simulated observations and thermodynamics modeling, they found that such biosignatures are difficult to detect around Sun-like stars and only marginally easier around M dwarfs under extremely low-noise conditions. Their work outlines critical challenges and paths forward for future life-detection missions.
Titan’s Changing Skies: New Insights from JWST and Keck
Scientists used JWST and Keck observations to study Titan’s atmosphere during late northern summer. They detected the CH₃ radical for the first time, observed CO and CO₂ emissions across a wide altitude range, and tracked evolving methane clouds. These findings reveal active weather, deep convection, and confirm long-standing predictions about Titan’s atmospheric composition and seasonal climate changes.
Reading Planetary Surfaces in the Skies: How Exoplanet Atmospheres Reveal Their Rocky Roots
Herbort and Sereinig model how rocky exoplanet surfaces influence their atmospheres, showing that specific gases and clouds in an atmosphere can hint at underlying rock types. Using chemical equilibrium models and simulated spectra, they find links between atmospheric composition and crustal minerals. This research helps interpret telescope data to infer exoplanet surface composition.
Sniffing Out Sulfur: JWST Detects Chemical Clues in the Atmosphere of TOI-270 d
L. Felix and colleagues used JWST data to study the atmosphere of TOI-270 d, a sub-Neptune exoplanet. They found strong signs of methane, carbon dioxide, and possibly sulfur-based molecules like CS₂. Their high-resolution analysis suggests a clear, metal-rich atmosphere, but further observations are needed to confirm its chemical makeup.
A Silicate Sky: Revisiting the Atmosphere of WASP-39 b with JWST
Ma et al. use a hybrid modeling approach to reinterpret JWST data from WASP-39 b, suggesting silicon monoxide (SiO) and silicate clouds explain key spectral features, previously attributed to sulfur dioxide. Their model fits observations well, highlighting the role of silicon-based chemistry and offering a new strategy for studying exoplanet atmospheres.
A Volcanic Atmosphere on L 98-59 b: Evidence from JWST Observations
Scientists used JWST to analyze L 98-59 b, a rocky exoplanet orbiting an M-dwarf star, and found evidence of a volcanic sulfur dioxide (SO₂) atmosphere. Tidal heating may fuel extreme volcanism, continuously replenishing the atmosphere. Their data suggests L 98-59 b could have a magma ocean beneath its surface. While not confirmed, additional observations could strengthen the case, offering new insights into how small planets retain atmospheres.
Unveiling Trends in Exoplanet Atmospheres with JWST
Researchers analyzed JWST data to uncover atmospheric trends in eight gas giant exoplanets, focusing on sulfur dioxide (SO₂), carbon dioxide (CO₂), and carbon monoxide (CO). They found that SO₂ correlates with cooler, smaller planets, while CO₂ highlights metallicity and CO dominates in hotter atmospheres. A new SO₂-L vs. CO₂-L diagram offers a framework for classifying exoplanet atmospheres, setting the stage for deeper insights as more data becomes available.
Exploring Uranus at New Angles: Insights from New Horizons' Observations
Samantha Hasler and colleagues analyzed unique high-phase-angle observations of Uranus captured by New Horizons in 2010, 2019, and 2023, revealing insights into Uranus’s energy balance and atmospheric characteristics. They found that Uranus’s brightness varies minimally across its surface and appears darker in certain filters than models predicted, suggesting limited large-scale atmospheric features. These observations, complemented by Hubble and amateur astronomer data, provide valuable benchmarks for future studies of ice giants, including distant exoplanets observed at similar angles.