[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.
Impact events
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.
![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.
Posted inAstrochemistry
Intimate Link Between Prebiotic Chemistry And Meteorites: Mechanisms Of Organic Molecule Formation
[Astrobiology (Journal) via PubMed] Whether meteorites brought ingredients necessary for the origin of life exogenously or they were produced endogenously on early Earth, having a prebiotic chemical inventory of organic […]
Posted inAstrobiology (general)
The Evolution Of Oxygen, Temperature, And Marine Aerobic Habitat For Animals Over The Last Billion Years Of Earth History
[Current Biology (Cell)] Atmospheric and ocean oxygen levels and temperature have changed considerably over Earth history, and many of these changes coincided with similarly dramatic changes in marine life.
Posted inImpact events
Impact Crater Hydrothermal Systems Support Rapid Microbial Enrichment and Diverse Metabolic Potential
[Geobiology ] Impact crater hydrothermal systems, formed after asteroid and comet impacts, have been proposed as promising habitats for life on early Earth and as key targets in the search […]
![Initial 𝑎c–𝑒c distribution of the 32,000 comets used in each end-to-end calculation. Dashed lines mark the semimajor axes of P7 and P8. The circular and eccentric planet calculations use identical comet initial states.-- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/10/Planetary.png?resize=1200%2C604&ssl=1)
Posted inComets and Asteroids
Planetary Eccentricity Enhances Inward Comet Transport But Suppresses Gentle Impacts
[astro-ph.EP] Comets can supply volatile and prebiotic material to rocky planets, but survival of fragile molecules depends on atmospheric entry and impact. Compact planet chains can transfer comets inward at […]
Posted inImpact events
JWST Studies Of Planet-shattering Collisions
[ESA]. In the early history of our Solar System, a Mars-sized object called Theia smashed into the infant Earth, vapourising massive amounts of rock and blasting it into space. Some […]
Posted inExtremeophiles and Extreme Environments
Whole-Genome Metagenomics Insights Revealed a Uranium Bio-remediating Cross-Domain Microbiome in the Dhala Impact Structure, India
[biorxiv.org] Meteorite impact structures on earth represent unique terrestrial analogues of extreme planetary environments where fractured lithologies, hydrothermal alteration, elevated concentrations of radionuclides, and prolonged water-rock interactions create ecological niches […]
Posted inImpact events
Meteor Hit Oklahoma 100 Million Years Later Than Previously Thought
[University of Texas at Austin] Researchers at The University of Texas at Austin have rewritten a small part of Oklahoma’s geologic history with global implications for ancient life.