![Atmospheric evolution with and without a post-disk giant impact. Panel 1: The common initial state for a rocky planet with a hydrogen-rich atmosphere. Panels 2a–4a: A giant impact deposits energy into the mantle and core, but the increase in gravitational binding energy dominates, allowing the planet to retain its hydrogen-rich atmosphere and evolve into a sub-Neptune (1.75−3.5 R⊕). Panels 2b–4b: In the absence of such an impact, the planet is less massive, loses its primordial atmosphere under sustained stellar irradiation, and becomes a super-Earth (1−1.75 R⊕). -- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/10/Retention.png?resize=1200%2C720&ssl=1)
[astro-ph.EP] Rocky planets the size of Earth or larger are expected to undergo one or more giant impacts during the final stages of their formation.
atmosphere
![Instantaneous zonally-averaged vertical cross-section of H2S (left) and HS (right). The black contour on the left panel corresponds to the bottom and top altitudes of the clouds (Ignatiev et al., 2009; Titov et al., 2018).-- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/10/The-impact.png?resize=1200%2C560&ssl=1)
Posted inVenus
The Impact Of The Sulfur Allotropes And Sulfur Hydrides On The Venus Cloud Chemistry
[astro-ph.EP] Venus is home to vivid sulfur chemistry, with SO2 as the major sulfur gas species and a global cloud layer between 47 and~70 km composed of H2SO4 and H2O. […]
Posted inLava / magma ocean / Volcanic Worlds
Shiny Lava Planet Challenges Astronomers’ Expectations
[University of Birmingham] Astronomers have discovered that a rocky lava planet once thought to be too extreme to have any atmosphere appears to be wrapped in a reflective layer of […]
Posted inTitan
The Physical And Chemical Structure Of Titan’s Upper Atmosphere: Energy Balance, Photochemistry And Jeans Escape
[astro-ph.EP] Titan’s upper atmospheric layers provide a unique opportunity to study how photochemistry, photoionisation, haze microphysics and escape processes shape its atmospheric chemical structure, providing a unique benchmark for understanding […]
Posted inExoplanets, -moons, -comets
The First Selection Of Optimal Targets For The Lazuli ExtraSolar Coronagraph’s Reflected Starlight Exoplanet Campaign
[astro-ph.EP] Direct detection and characterization of exoplanet atmospheres via reflected starlight enables probes of composition of mature exoplanet systems (since flux is decoupled from age) at closer separations than via […]
![The Pandora Observatory in stowed configuration is designed to meet the ESPA Grande volume limits. Three renders show the observatory from different angles with the solar array stowed. The spacecraft bus encompasses the lower section of the observatory, with the payload attached to the bus via an interface plate. -- [astro-ph.IM]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/10/The-Pandora-SmallSat.jpg?resize=1200%2C722&ssl=1)
Posted inCubesats and smallsats
The Pandora SmallSat: Post-launch Operations And Mission Update
[astro-ph.IM] The Pandora SmallSat is a NASA flight project designed to study the atmospheres of exoplanets. Transmission spectroscopy of transiting exoplanets provides our best opportunity to identify the makeup of […]
Posted inExoplanets, -moons, -comets
Systematic Uncertainties in Rocky Exoplanet Reflected Light from Incomplete Laboratory BRDF Measurements
[astro-ph.EP] The first observations of short-period rocky exoplanets have initiated the era of terrestrial exoplanet characterization. The interpretation of these observations relies on forward models used in atmospheric and surface […]
![Longitude–height structure of the rotational component of the stationary s = 1 zonal wind anomaly, near the Huygens latitude band during Ls = 290◦–310◦ -- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/10/Topographically.png?resize=1200%2C719&ssl=1)
Posted inTitan
Topographically Forced Stationary Waves Can Explain The Near-Surface Zonal Winds Observed By Huygens On Titan
[astro-ph.EP] Titan’s equatorial superrotation is associated with climatological retrograde (westward) near-surface winds at low latitudes, as consistently simulated by Titan general circulation models.
Posted inGaia - Planetary Perspectives
How Life On Earth Experiences Climate Change
[Stockholm University] Climate change can look very different at the scale of a forest, field or hillside. A new review shows how changes in vegetation and atmospheric conditions can cause […]
![Image credit: Izraelevitz et al. 2024 - -[astro-ph.IM]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/10/The-science.png?resize=1200%2C718&ssl=1)
Posted inVenus
The Science Case For An In-situ Measurement Platform In The Venus Clouds
[astro-ph.IM] The next step for Venus exploration after the remote sensing missions of the early 2030s will be in-situ aerial platforms, the Venus equivalent of rovers for Mars.