[NASA] Terra Sirenum is a heavily cratered region of Mars’ ancient Southern Highlands. A blanket of dust, possibly cemented by ice, covers much of the ancient bedrock in these Martian […]
Astrogeology
Posted inImaging & Spectroscopy
Reconciling Giant Impacts with the Radius Valley: The Role of Silicate-Hydrogen Miscibility for Sub-Neptunes
[astro-ph.EP] Giant impacts are believed to play a major role in the assembly, long-term orbital stability, and resonant structure of exoplanetary systems.
![Mass fraction of planets formed at 140K (top) and 300K (bottom) around Star B in pair 69. The composition of the planet is determined by the relative abundances of the elements the planet accreted. From left to right we change the stellar abundances according to their error bars in table B.2, where “Minus” corresponds to [X/H]−σ, “Normal” to [X/H], and “Plus” to [X/H]+σ. -- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/10/Diversity.png?resize=1200%2C720&ssl=1)
Posted inExoplanets, -moons, -comets
Diversity Of Planetary Origins And Compositions Traced By Stellar Abundance Differences Of Co-natal Star Systems
[astro-ph.EP] Co-natal stars, wide binaries that form from the same molecular cloud, should harbor the same stellar composition. Observations indicate stellar abundance differences in a small fraction of these co-natal […]
Posted inAtmospheres, Climate, Weather
Coupled Evolution Of Earth’s H2-rich Proto-atmosphere And Oxidized Magma Ocean
[astro-ph.EP] Giant impacts during Earth’s final accretion likely generated global magma oceans, where the disproportionation of Fe2+ at lower-mantle pressures and segregation of the resulting metallic iron into the core […]
Posted inMars
University of New Mexico Scientists help Uncover 4.1 billion-year-old Martian Meteorite Revealing Clues to Planet’s Ancient Past
[UNM]. Scientists at the University of New Mexico have played a key role in identifying a rare, 4.1-billion-year-old Martian meteorite that provides new evidence that the Red Planet may have […]
Posted inPanspermia
Comets Probably Didn’t Seed Life On Earth After All, New Study Suggests
[University of Cambridge]. Comets didn’t seed life on Earth after all, a new study suggests, potentially overturning a century-old idea.
![[LEFT] Diagram of a pixel component from a microbolometer array showing the absorbing surface, electrically conducting bridge connecting the absorber to the readout electronics, and the mirrored surface below the absorber. [RIGHT] A digital render of the Enceladus Thermal Mapper instrument. The arrow shows the location of the filter assembly. -- [astro-ph.IM]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/10/Tailoring.png?resize=1200%2C606&ssl=1)
Posted inEnceladus
Tailoring Infra-Red Filters for Global Mapping of Enceladus’ Thermal Environment
[astro-ph.IM]. We present the results of an initial study into the feasibility and design of the Enceladus Thermal Mapper (ETM) instrument, designed to provide detailed temperature data for Enceladus, an […]
Posted inMars
Preparing To Drill At ‘Nazca’ On Mars
[NASA]. Curiosity Blog, Sols 5043-5049: Preparing to Drill at ‘Nazca’ Earth planning date: Friday, Oct. 16, 2026
Posted inAstrogeology
Research Suggests Earth May Have Formed Much Of Its Water As The Planet Grew
[University of New Mexico] Earth may have produced much of its water during the planet’s formation, as rocky pebbles reacted with the hydrogen-rich atmosphere surrounding the young planet, according to […]
![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)
Posted inImpact events
Retention Of Primordial Atmospheres Through Giant Impacts
[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.