![The multiple roles of methanogens in the modern-day carbon cycle. Processes shown in red contribute to greenhouse gas production. Part of the methane is removed through microbial methane oxidation (A)MO and photochemical reactions, where e is a generic electron donor (e.g., arsenate or sulfate) that is reduced to eH. Processes depicted in green sequester CO2, storing it long-term as carbonates. The size of the arrows relates to the relative biogeochemical importance of the process. The metabolic activity of methanogens may locally alter pH and produce copious amounts of EPS (seen as a veil surrounding the cells in the microphotograph (yellow arrow)). These EPS bind cations (e.g., Ca, Mg) and act as nucleation site, while elevated pH enhances the carbonate precipitation in microbial mats [196]. This contribution by methanogens may ultimately produce microbialites [183] -- preprints.org](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/01/Methanogens-Through-Geological.png?resize=1200%2C720&ssl=1)
Methanogens, also known as methanogenic archaea, are among the most ancient and widespread microorganisms, despite their particular requirements for growth. These oxygen-sensitive microorganisms have impacted climate and biogeochemical cycles throughout […]
Fossils & Paleontology
Posted inArtemis & Lunar Exploration, Astrochemistry, Astrogeology, Biosignatures & Paleobiology, Exploration Gear & Tech, Fossils & Paleontology, Missions & Hardware, Moon, Panspermia, Planetary Protection & Biosafety, Press Release
Lunar Spacecraft Exhaust Could Obscure Clues To Origins Of Life
Over half of the exhaust methane from lunar spacecraft could end up contaminating areas ofthe moon that might otherwise yield clues about the origins of earthly life, according toa recent […]
Posted inAstrochemistry, Astrogeology, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Desert Worlds, Fossils & Paleontology, Imaging & Spectroscopy, Mars, Missions & Hardware, Robotics/Rovers/UAVs, Status Report
Mars Curiosity Rover Observes Sulfur Crystals
This image was captured by Curiosity’s Mars Hand Lens Imager (MAHLI), a camera on the end of its robotic arm, on June 4, 2024, the 4,205th Martian day, or sol, […]
Posted inAnalog Studies, Arctic / Antarctic / Alpine, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Extremeophiles and Extreme Environments, Fossils & Paleontology, Genomics, Proteomics, Bioinformatics, Habitable Zones, Icy Worlds, Microbiology & Virology, Status Report
Ancient Metagenomics Reveals Subglacial Microbiomes Driven By Oxygen Availability
Beneath Earth’s glaciers and ice sheets lies an aquatic realm where ice, water, rock, and microbial life interact, driving chemical reactions that can collectively influence the global carbon cycle, polar […]
![Selected examples of different chemically oscillating reactions (COR) with patterns produced during the decarboxylation of malonic acid [1 M] using a solution of sodium bromate [1 M], sulfuric acid [0.33 M], sodium bromide [1 M], and phenanthroline ferrous sulfate [0.025 M]. (A) Spot proliferation pattern in a 10 cm diameter petri dish. (B) A few spots of different sizes formed within half a minute. (C) Pairs of images of a COR in a petri dish with insets taken five seconds apart showing the radial diffusion of circularly concentric spots. (D) Spots spanning from sub-millimeter (white arrows) to centimeter sizes. (E) Twinned circularly concentric spots (white dashed line shows the twin plane). A few bubbles of CO2 produced by the reaction can be seen. (F) Circularly concentric spot with short color gradients in laminations. (G) Circularly concentric spot with long color gradients in laminations. (H) Circularly concentric spot with dozens of laminations and CO2 bubbles, formed later (at ∼26 min) during another reaction. -- GeoScience World](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/01/Authigenic-biosignatures-of-microbial.png?resize=1200%2C718&ssl=1)
Posted inBiogeochemical Cycles & Geobiology, Biophysics, Biosignatures & Paleobiology, Fossils & Paleontology, Microbiology & Virology, Origin & Evolution of Life, Status Report
Authigenic Biosignatures Of Microbial Biomass Preserved As Carbonate Ooids Formed By Abiotic Chemically Oscillating Reactions Throughout Earth History
Ooids are small spheroidal carbonate grains that have circularly concentric and radially aligned crystals. Oolitic carbonates are commonly associated with fossils or organic matter, which has led to hypothetical formation […]
Posted inBiosignatures & Paleobiology, Courses, Fossils & Paleontology, Status Report, Video, Audio, Webcasts, Podcasts
LIFE NASA RCN Seminar 6 January 2026
Join the 2026 LIFE NASA RCN Seminar Series! This month’s speakers are Dr. Ilya Bobrovskiy and Dr. Tharika Liyanage.
Posted inBiochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Fossils & Paleontology, Genomics, Proteomics, Bioinformatics, Microbiology & Virology, Origin & Evolution of Life, Status Report
Designing Peptide Fossils That Model the Evolution of the Bacterial Ferredoxin Fold
Electron transfer coupled to redox chemistry is at the heart of metabolism. The proteins responsible for moving electrons (protein electron carriers) must have emerged at the origin of life.
Posted inAnalog Studies, Arctic / Antarctic / Alpine, Away Teams & Field Reports, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Caves, Craters, Mountains, Subsurface, Lava Tubes, Cryobiology, Exploration Gear & Tech, Extremeophiles and Extreme Environments, Fossils & Paleontology, Habitable Zones, Mapping, Geodesy, Cartography, Bathymetry, Origin & Evolution of Life, Sample Return, Status Report
Subsurface Life On Earth As A Key To Unlock Extraterrestrial Mysteries
The first forms of life on Earth were microbial, preceding the evolution of multicellular life by more than two billion years.
Posted inAnalog Studies, Away Teams & Field Reports, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Fossils & Paleontology, Habitable Zones, Microbiology & Virology, Origin & Evolution of Life, Press Release, Sample Return
Study Showcases Resilience and Rapid Growth of “Living Rocks”
South Africa is home to some of the oldest evidence of life on Earth, contained in rocky, often layered outcroppings called microbialites. Like coral reefs, these complex “living rocks” are […]
Posted inBiogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Fossils & Paleontology, Genomics, Proteomics, Bioinformatics, Microbiology & Virology, Origin & Evolution of Life, Press Release
Rare Earth Elements – Of Peptides And The Origins Of Life
Elements from the group of rare earth metals are of great importance today, also in technical applications. The Bioinorganic Chemistry group at Heinrich Heine University Düsseldorf (HHU) is conducting diverse […]