Archean – My WordPress Site

PIXL micro-XRF observation from the third “Apollo Temple” scan (a,b), alongside a SHERLOC WATSON color image for context (c). An RGB composite shows the areas with relative enrichment of FeOT, SO3, and SiO2 where brownish tones highlight Fe-sulfide (a). Zones of Ni enrichment are seen in yellow (b) and marked with white arrows (a,b,c). Dashed black box shows the approximate area of the PIXL scan (c). Image Credit: NASA/JPL-Caltech.

Astrogeology, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Habitable Zones, Imaging & Spectroscopy, Mars, Robotics/Rovers/UAVs

Strong Nickel Enrichment Co-located With Redox-organic Interactions In Neretva Vallis, Mars

by Keith CowingApril 8, 2026April 8, 2026

In 2024, NASA’s Perseverance rover explored Neretva Vallis, an ancient river channel that once transported water into Jezero crater.

Archean Earth - Grok via Astrobiology.com

Astrogeology, Atmospheres, Climate, Weather, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Fossils & Paleontology, Habitable Zones, Origin & Evolution of Life, Water/Hycean Worlds & Oceanography

Atmospheric Oxygen And Methane On The Early Earth

by Keith CowingMarch 25, 2026March 25, 2026

HCN rainout rate over the conjoint parameter space of stellar effective temperature (Teff ) and effective solar flux in current Earth values (Seff ) and C/O ratio. a) Baseline Archean Earth C/O ratio of 0.514 with the black box on the plot and gray horizontal line on the colourbar representing the Archean Earth model and estimated maximum HCN delivery rate by meteorites, respectively; b) Histogram of all simulated HCN rainout rates with gray, black, and pink vertical dashed lines representing the estimated maximum exogenous HCN delivery rate, the Archean Earth model, and the median HCN rainout rate, respectively. -- astro-ph.EP

Astrochemistry, Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Genomics, Proteomics, Bioinformatics, Habitable Zones, Impact events, Meteorites & Asteroids, Origin & Evolution of Life

Atmospheric Supply Of HCN Is Not The Rate Limiting Step For Prebiotic Chemistry Across Rocky Exoplanets

by Keith CowingMarch 22, 2026March 22, 2026

Left: Reflectance spectra of photosynthetic organisms on rock, mineral, and snow/ice abiotic surfaces with Archean, Proterozoic, and Modern atmospheric compositions (planetary spectra provided by Anna Grace Ulses, Univ. of Washington). The thick angled lines show the pigment ”edge” features in the spectrum. Right: Top: purple anoxygenic phototrophs with bacteriochlorophyll pigments absorbance and reflectance features at 805-880 nm at 15% planet coverage under an Archean atmosphere with 50% cloud cover. Middle: cyanobacterial microbial mat (oxygenic phototroph) with chlorophyll a absorption at 660-680 nm at 15% coverage under a Proterozoic atmosphere with 50% cloud cover. Note that the 3-D structure of the mat is effective at scattering light to create a ”red edge” feature similar to the vegetation red edge (VRE) shown in the bottom panel. Top two spectra provided by N. Parenteau, unpublished data. -- astro-ph.IM

Astronomy & Telescopes, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Icy Worlds, Imaging & Spectroscopy, Microbiology & Virology, Water/Hycean Worlds & Oceanography

Habitable Worlds Observatory Living Worlds Working Group: Surface Biosignatures on Potentially Habitable Exoplanets

by Keith CowingJanuary 15, 2026January 15, 2026

The spectrum of UV light available at Earth’s surface before the origin of life at approximately 3.9 Ga and until at least 2.9 Ga

Astrogeology, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Origin & Evolution of Life, Stellar Cartography

Abiogenesis On Different Star Types; a Dissipative Photochemical Perspective

by Keith CowingNovember 18, 2025November 18, 2025

"To bridge dilution between environments, we specify mobile “holding pens” (green-rust/iron flocs, silica mats, pumice rafts, and sea-surface microlayer/foam) that concentrate, shuttle, and release prebiotic cargo into shoreline pools." -- Grok via Astrobiology.com

Analog Studies, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biophysics, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Extremeophiles and Extreme Environments, Genomics, Proteomics, Bioinformatics, Habitable Zones, Origin & Evolution of Life, Water/Hycean Worlds & Oceanography

A Hybrid Iron/Green-Rust-Urea Model for Prebiotic Chemistry: A Synthesis of Testable Pathways for Planetary Astrobiology

by Keith CowingOctober 20, 2025October 20, 2025

Upper panel: UV flux reaching the surface of the planet TOI-700 d for an Archean atmosphere, depicted in purple (fUV=1) and red (fUV=10), and a modern Earth-like atmosphere, in green (fUV=1) and blue (fUV=10). The different surface pressures, namely 4.0, 2.0, 1.0, and 0.5, are represented by tones gradually shifting towards lighter shades, indicating a transition from higher to lower pressure. The solar flux reaching both Earth’s exosphere and surface is depicted by solid black line and dashed black line, respectively, primarily for the purpose of comparison. Lower panel: a blowup of the flux scale depicted on the upper panel. -- astro-ph.EP

Analog Studies, Astronomy & Telescopes, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones

Evaluating Habitability and Biosignature Detection on TOI-700 d: The Role of UV Environment and Atmospheric Pressure

by Keith CowingOctober 17, 2025October 17, 2025

The solid curve represents the average dissolved oceanic Ni concentration (nmol L−1). Light blue indicates pO2 (Present Atmospheric Level, PAL). Changes in urea concentration are indicated by a red gradient (darker red represents higher concentrations). The average dissolved oceanic Ni concentration is plotted on data from ref. 26, and the Oxygen evolution curve is from ref. 1. Solar Lyman α flux is from ref. 83. -- Nature

Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Gaia - Planetary Perspectives, Habitable Zones, Origin & Evolution of Life, Water/Hycean Worlds & Oceanography

Earth’s Oxygen Boom: A Fresh Perspective For A Billion-year-old Problem

by Keith CowingOctober 10, 2025October 10, 2025

A panoramic picture of one of five hot springs during winter, showing the source water and CO2 bubbles. Credit Fatima Li-Hau, ELSI

Atmospheres, Climate, Weather, Away Teams & Field Reports, Biogeochemical Cycles & Geobiology, Biophysics, Biosignatures & Paleobiology, Extremeophiles and Extreme Environments, Habitable Zones, Microbiology & Virology, Origin & Evolution of Life

Hot Springs In Japan Give Insight Into Ancient Microbial Life On Earth

by Keith CowingSeptember 26, 2025September 26, 2025

Examples of training reflection spectra for Earth-like exoplanets in the Archean (left), Proterozoic (center), and Modern (right) eras, observed with LUVOIR-B (top row) and Habex/SS (bottom row). Colored lines represent the total radiance 𝐴(𝜆), while points with error bars correspond to 𝐴noisy (𝜆) as defined by Equation 13. -- astro-ph.EP

AI - Data - Apps - Cybernetics, Analog Studies, Astrogeology, Astronomy & Telescopes, Atmospheres, Climate, Weather, Biosignatures & Paleobiology, Habitable Zones, Imaging & Spectroscopy

Towards the Habitable Worlds Observatory: 1D CNN Retrieval of Reflection Spectra from Evolving Earth Analogs

by Keith CowingAugust 4, 2025August 4, 2025