[LIFE] Reports of viable microorganisms from ancient halite create an unusual test of the biological limits of cellular survival.
Fossils & Paleontology
![Radiogenic dose and the benefit of drilling. (a) GCR dose versus depth for constant-depth and steadily exhuming horizons, compared with the depth-independent radiogenic dose. Shading spans the radiogenic dose of the baseline composition at 3 Ga (0.9 MGy) and that of the regional GRS abundances at 3.9 Ga (5.6 MGy). Where a curve crosses the radiogenic level, the two doses are equal. (b) Total-dose reduction at 100–101 and 199–200 cm versus exposure age; dashed lines are the GCR-only shielding factors. Dotted lines mark effective ages for 10 and 100 nm yr−1 exhumation. -- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/10/Radiation.png?resize=1200%2C720&ssl=1)
Posted inMars
Radiation Limits On Amino Acid Preservation And Chiral Measurement At Oxia Planum
[astro-ph.EP] Amino acid enantiomeric excess (EE) is a potential biosignature, but its measurement requires sufficient surviving material as well as preserved chirality.
Posted inBiogeochemical Cycles & Geobiology
Material Cycling Across Earth’s Spheres And Triggers Of Cambrian Explosion: A Tectonic Perspective
[ELSP] A comprehensive model of the Cambrian explosion featuring “multi-factors coupling and multi-sphere driving”. Supercontinent breakup and mantle plume activity served as the initial trigger of environmental change in the […]
Posted inFossils & Paleontology
Protocells Reproduce Morphological And Chemical Signatures Of Early Microfossils
[biorxiv.org] Identification of early microfossils relies on morphological and chemical criteria assumed to be unique to life, but whether abiotic microstructures can satisfy these criteria has not been rigorously tested.
Posted inBiogeochemical Cycles & Geobiology
Activity And Diversity Of Sulfate- and Methane-based Pathways Of Anaerobic Chitin And N-acetylglucosamine Degradation In Marine Sediments
[American Society of Microbiology] Sulfate reduction is estimated to account for half of the organic carbon respiration in anoxic, organic-rich ocean sediments. Sulfate-reducing microorganisms (SRMs) typically oxidize simple carbon compounds, […]
Posted inAtmospheres, Climate, Weather
Ancient Seas Reveal Times When The Earth Rapidly Shifted Relative To Its Axis
[AAAS] Ancient sea-level changes provide new evidence that during the Jurassic and Cretaceous, Earth underwent episodes of rapid “true polar wander” (TPW).
Posted inAway Teams & Field Reports
NASA Scientists Search For Clues About Mars’ Past In Scotland
[NASA] This summer, NASA scientists headed to the Scottish Highlands to follow up on last year’s announcement of potential biosignatures on Mars and prepare for future research.
Posted inWater/Hycean Worlds & Oceanography
How Ocean Chemistry On Earth Helped Life Keep Breathing
[UC Riverside] Scientists have helped solve a longstanding mystery about how Earth remained habitable after oxygen first accumulated in its atmosphere more than 2 billion years ago, providing evidence that […]
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.
Posted inBiosignatures & Paleobiology
Carbon and Sulfur Isotopes of Microfossils and Pyrites from Neoarchean Cherts: Microbial Diversity in an Ancient Deep-Marine Environment
[Astrobiology (Journal) via PubMed] The 2.52 Ga Gamohaan Formation in South Africa offers critical insights into microbial ecosystems that inhabited deep-marine environments during the late Archean.