[Michigan State University] For decades, scientists have studied iron preserved in ancient rocks to reconstruct how Earth’s oceans and atmosphere became rich in oxygen. A new study suggests iron has […]
biogeochemistry
Posted inGaia - Planetary Perspectives
Global Carbon Fixation In Earth’s Subsurface Biosphere
[biorxiv.org] The subsurface of our planet hosts 15% of Earth’s biomass and plays a key role in mediating the exchange of volatiles and elements between deep, long-residence-time geological reservoirs and […]
![This illustration contrasts Earth's oceans during ancient glaciations (left) with deglacial conditions (right). Syracuse University researchers found that oceans lost oxygen not just during warm periods, but repeatedly during Earth's deepest ice ages, a pattern preserved in manganese deposits within ancient seafloor rock. (Courtesy: Xubin Wang, generated with AI)-- [Syracuse University]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/08/Metal-deposits.jpg?resize=1200%2C720&ssl=1)
Posted inBiogeochemical Cycles & Geobiology
Metal Deposits Linked To Oceanic Oxygen Loss During Ancient Ice Ages
[Syracuse University] An international team of researchers analyzed manganese and other chemical signatures preserved in more than 27,000 ancient seafloor samples collected from six continents. Across six major glaciations spanning […]
Posted inBiosignatures & Paleobiology
Micropeloidal Textures – Definition, Formation And Potential As Biosignatures
[Earth-Science Reviews] Microbial biosignatures result from the interactions between microbial populations, metabolic processes, organic and mineral products, and the surrounding physicochemical environment.
Posted inHabitable Zones
Euhabitability: A New Term To Aid In The Search For Life In Addition To The Habitable Zone Framework
[Space Science Reviews] The search for life on exoplanets is difficult due to observational limitations stemming from vast separating distances. The Habitable Zone (HZ) is a simplifying framework for identifying […]
Posted inVenus
Development Of A Data Retrieval Algorithm For Venus Nephelometry In Preparation For The Rocket Lab Mission To Venus
[Science Direct] The Rocket Lab Mission to Venus (RLMV) will carry a single primary instrument, the Autofluorescence Nephelometer (AFN), to interpret atmospheric particle properties from light-scattering measurements. This process is […]
Posted inAstrogeology
Diverging Mineral Chemistry of Iron and Nickel Throughout Earth’s Changing Redox Conditions Reveals Foundation for Their Evolution as Protein Cofactors
[LIFE] Iron (Fe) and nickel (Ni) were both foundational to early metabolism, yet their biological trajectories diverged as Earth’s surface redox state changed. Here, we integrate mineral chemistry network analysis, […]
![Deep-sea microbial sample processing. Detailed sample processing steps for HPG assimilating cells and total cell counts are denoted in grey and black arrows/squares, respectively. Processing steps and samples used for metagenomic sequencing are denoted in light-blue arrows and squares. “Whole sample” correspond to triplicate 50 ml aliquots, each filtered onto a 0.22 μm filter directly from the cryopreserved material, and then released with 200 μl of 0.025% (v/v) Tween 20 in PBS to be processed through MDA and DNA sequencing; “all cells” correspond to samples of cryopreserved material that were stained with a DNA dye, collected on a 0.22 μm filter, processed through the BONCAT labelling assay, and then sorted by flow cytometry, aiming to select events that presented the DNA dye; “BONCAT+” cell samples originated from the same material as ‘all cells’, but their sorting aimed for events that presented both the DNA dye and the fluorescent dye Alexa-Fluor 488 (attached to the HPG incorporated by the active cells). The selection of BONCAT+ cells was established for each sample based on the level of BONCAT background labelling to the microbial community when not exposed to HPG, or when fixed before being exposed to HPG (i.e. reflecting the adhesion of the fluorescent label to cells that did not incorporate HPG). -- [ISME Journal via PubMed]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/07/Sample-Return.png?resize=1200%2C719&ssl=1)
Posted inSample Return
Sample Return: Minimizing Decompression And Warming During Deep Seawater Collection Increases Abundance And Activity Of Autochthonous Bacteria And Archaea
[ISME Journal via PubMed] The deep ocean hosts autochthonous pressure-adapted microorganisms that are unique to this environment, as well as allochthonous pressure-sensitive members transported from shallow depths by vertical advection […]
Posted inBiochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Desert Worlds, Habitable Zones, Imaging & Spectroscopy, Mars, Missions & Hardware
Organic Carbon Detected In The Bright Angel Formation On Mars
In September of last year, NASA announced that its Perseverance rover discovered a potential biosignature, which is a substance or structure that might have a biological origin.
Posted inAstrogeology, Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Mars, Meteorites & Asteroids, Origin & Evolution of Life, Panspermia, Sample Return, Status Report
Mars Organic Geochemistry-Are We Alone, and Where Did We Come From?
This review of martian organic geochemistry aims to contextualize recent findings of organic molecules in martian meteorites and from Mars missions within the broader study of origins of life on […]