Biogeochemical Cycles & Geobiology Archives

Sensitivity of the Fe anomaly of the overturned silicate layer with respect to the rest of the mantle. (a) Sensitivity of this anomaly vs. mantle thickness. Mars and Earth sizes are represented for clarity. Note that the final anomaly is expected to be maximum when the thickness of the mantle is that of the critical Rayleigh number DRac and tends to 0 at infinite thickness. (b) Sensitivity of the Fe# anomaly vs. the bulk Fe# of the mantle. Earth and Mars compositions are represented for clarity. We extend compositions to lower bulk Fe# than Earth according to (R. J. Spaargaren et al. 2023) (dotted line, see text). All other properties remain fixed at Earth-like values except for gravity acceleration which is scaled linearly to planet size (assumed to be proportional to mantle thickness). The density anomaly secondary axis is valid for both, panel (a) and (b). -- astro-ph.EP

Astrogeology, Biogeochemical Cycles & Geobiology, Mapping, Geodesy, Cartography, Bathymetry, Mars, Press Release

Earth And Mars Interior Structures Set By Re-melting Of The First Solid Mantle

by Keith CowingMay 8, 2026May 8, 2026

Magma ocean crystallisation sets up the early structure and long-term evolution of terrestrial planets. Recent seismic evidence signals the presence of a silicate layer at the base of Mars’ mantle.

Curiosity's drill stuck in a rock named Atacama -- NASA/JPL-Caltech/MSSS

Astrogeology, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Imaging & Spectroscopy, Mars, Missions & Hardware, Robotics/Rovers/UAVs, Sample Return, Status Report

Curiosity Astrobiology Rover Gets Stuck And Unstuck In ‘Atacama’

by Keith CowingMay 7, 2026May 17, 2026

Earth planning date: Friday, May 1, 2026 Chile’s Atacama desert is the driest mid-latitude desert in the world, receiving only 15 millimeters (0.59 inches) of precipitation per year. Only the […]

Secular evolution of terrestrial boron reservoirs. Comparison of boron concentrations and speciation for early Earth (A) and after the emergence of peraluminous continental crust (B). -- Terra Nova

Astrochemistry, Astrogeology, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Fossils & Paleontology, Genomics, Proteomics, Bioinformatics, Habitable Zones, Origin & Evolution of Life, Press Release, Water/Hycean Worlds & Oceanography

How The Rise Of Continents May Have Set The Stage For Life On Earth

by Keith CowingMay 7, 2026May 7, 2026

Earth’s earliest continents may have set the chemical stage for life by regulating boron levels in ancient oceans, a new study in Terra Nova suggests.

Sediment core sampling procedure adapted from the expedition’s press release (Schmidt Ocean Institute, SOI), licensed under CC BY 4.0 -- CAB

Analog Studies, Away Teams & Field Reports, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exploration Gear & Tech, Extremeophiles and Extreme Environments, Genomics, Proteomics, Bioinformatics, Habitable Zones, Imaging & Spectroscopy, Mapping, Geodesy, Cartography, Bathymetry, Microbiology & Virology, Nomenclature, Systematics, Natural History, Press Release, ROVs/Submersibles/Diving, Sample Return, Water/Hycean Worlds & Oceanography

New Sulfur-dependent Ecosystem In A Gas Vent In The Depths Of The Chilean Pacific

by Keith CowingMay 7, 2026May 7, 2026

Unlike most similar emanations described to date, this one shows no evidence of methane emission or consumption. The absence of this molecule and its abundance of sulfur make it a […]

Relative entropy shift applied by the Mazevet et al. (2019) correction (Eq. (17)) across the water phase diagram in plog10 T, log10 Pq space. The colormap is logarithmic between 10´3 and 10, with the upper bound saturating along a narrow ridge where the aqua baseline entropy nearly vanishes. Solid white lines mark the phase boundaries of the underlying aqua table; labels identify the fields of ices, liquid, vapor, and supercritical water. Dashed lime contours with inline labels mark the analytic gate w7 that selects where the patch is applied: w7“0 outside the patch (no shift) and w7“1 inside its core (full correction). The figure shows that the correction is concentrated in a localized strip of the supercritical regime between ice X and the Brown (2018) fluid, leaving the rest of the aqua table untouched. -- astro-ph.EP

Astrogeology, Biogeochemical Cycles & Geobiology, Exoplanets, -moons, -comets, Status Report

PALEOS: Multiphase Equations of State and Mass-Radius Relations for Exoplanet Interiors

by Keith CowingMay 7, 2026May 7, 2026

Modeling the interior of a rocky or water-rich exoplanet is a thermodynamic closure problem: every layer’s density, temperature gradient, and phase must follow from an equation of state (EoS) that […]

Transmission spectrum of TOI-1130b with the best-fit free chemistry, equilibrium chemistry and grid model overplotted (left) and comparison between retrieved abundances from the three model fits for TOI-1130b (right). The points shown on the right panel are the best fit mass fractions from the free retrieval. The H2O and CO2 posterior distributions shows a lower limit, where as the other molecules show gaussian distributions. Therefore H2O and CO2 data points are shown with upper arrows. The solid lines show chemical abundance profiles from equilibrium chemistry and the dashed lines show the chemical profiles from the self-consistent forward model grid. -- astro-ph.EP

Astrochemistry, Astrogeology, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Icy Worlds, Imaging & Spectroscopy, Status Report

JWST Unveils A High Mean Molecular Weight Atmosphere For Mini-Neptune TOI-1130b: Evidence For Formation Beyond The Water Ice Line

by Keith CowingMay 6, 2026May 6, 2026

We present the combined JWST/NIRSpec G395H and NIRISS SOSS transmission spectrum of a warm mini-Neptune, TOI-1130b (3.66 R⊕, 19.8 M⊕, Teq∼825 K). It is part of a rare and unique […]

NOAA Ocean Exploration’s recently released environmental DNA (eDNA) data help us better understand what lives in the deep ocean. Among these data is evidence of invertebrates, like Crossota millsae (the jellyfish seen here); fish; marine mammals; microbes; and more. While some of the organisms found in these data have been seen on previous expeditions on NOAA Ship Okeanos Explorer, others, like Macropinna microstoma (barreleye fish), remain elusive. Image courtesy of NOAA Ocean Exploration, 2019 Southeastern U.S. Deep-sea Exploration. Download largest version (jpg, 893.9 KB).

Analog Studies, Atmospheres, Climate, Weather, Away Teams & Field Reports, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exploration Gear & Tech, Gaia - Planetary Perspectives, Genomics, Proteomics, Bioinformatics, Habitable Zones, Microbiology & Virology, Press Release, ROVs/Submersibles/Diving, Sample Return, Tricorders & Sensors, Water/Hycean Worlds & Oceanography

Water World Genomics: Unlocking Ocean Secrets With eDNA

by Keith CowingMay 6, 2026May 6, 2026

Editor’s note: with recent speculation about the potential habitability of other worlds and understanding the processes whereby other biospheres arise and evolve, thought needs to be given to developing sensor […]

Maps of annual mean sea ice and continental precipitation (A) and annual mean sea surface temperature (in ocean regions) and surface air temperature (over continents) (B) for simulations with Earth-like ocean salinity (35 g/kg) and obliquity (23.5◦ ), at Archean instellation on the left and present-day instellation on the right. Land contours mapped in the figure (in black) are more detailed than the actual Earth-like continent configuration used in the model. -- astro-ph.EP

Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Gaia - Planetary Perspectives, Habitable Zones, Icy Worlds, Imaging & Spectroscopy, Status Report, Terraforming & Geoengineering, Water/Hycean Worlds & Oceanography

Synergistic Effects of Ocean Salinity and Planetary Obliquity Enhance Habitability of Cold Exo-Earths

by Keith CowingMay 6, 2026May 6, 2026

Past work has shown that ocean salinity and planetary obliquity both influence the climates of Earth-like exoplanets throughout the habitable zone of Sun-like stars. The effects of salinity and obliquity […]

Hydrothermal vents on the ocean floor spew black smoke, which forms when super-hot vent water hits the cold ocean. Scientists view them as candidates for where life may have started, because they provide heat, minerals and chemical energy that early life could have used to form and grow. Photo: Richard Lutz

Astrochemistry, Astrogeology, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Comets and Asteroids, Extinction events, Impact events, Meteorites & Asteroids, Origin & Evolution of Life, Press Release, Water/Hycean Worlds & Oceanography

Did Impacts From Meteors Help Start Life On Earth?

by Keith CowingMay 6, 2026May 6, 2026

Meteor impacts may have helped spark life on Earth, creating hot, chemical-rich environments where the first living cells could take shape, according to research integrated by a recent Rutgers University […]

Shapes at the start of bars correspond to the midpoint date (or right node date for speciation events) of the earliest gene event recorded for genes within a given group.

Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biophysics, Biosignatures & Paleobiology, Extremeophiles and Extreme Environments, Genomics, Proteomics, Bioinformatics, Origin & Evolution of Life, Press Release

Early Life On Earth Relied On A Surprisingly Scarce Metal: Molybdenum

by Keith CowingMay 6, 2026May 6, 2026

A new study from researchers at the University of Wisconsin–Madison shows that 3.4 billion years ago, life on Earth relied on a metal called molybdenum, despite its limited availability at […]

Biogeochemical Cycles & Geobiology

Earth And Mars Interior Structures Set By Re-melting Of The First Solid Mantle

Curiosity Astrobiology Rover Gets Stuck And Unstuck In ‘Atacama’

How The Rise Of Continents May Have Set The Stage For Life On Earth

New Sulfur-dependent Ecosystem In A Gas Vent In The Depths Of The Chilean Pacific

PALEOS: Multiphase Equations of State and Mass-Radius Relations for Exoplanet Interiors

JWST Unveils A High Mean Molecular Weight Atmosphere For Mini-Neptune TOI-1130b: Evidence For Formation Beyond The Water Ice Line

Water World Genomics: Unlocking Ocean Secrets With eDNA

Synergistic Effects of Ocean Salinity and Planetary Obliquity Enhance Habitability of Cold Exo-Earths

Did Impacts From Meteors Help Start Life On Earth?

Early Life On Earth Relied On A Surprisingly Scarce Metal: Molybdenum

Determining The “Biosignature Threshold” For Life Detection On Biotic, Abiotic, or Prebiotic Worlds.

Icy Ocean Planet Research: NASA ROSES-25 Amendment 71: New Opportunity A.16 Cryosphere

Global Carbon Fixation In Earth’s Subsurface Biosphere

tinyRNA-seq: An Optimized Approach To Sequencing Tiny RNAs And Primitive RNA Genomes

Stellar Flares Rather Than High Tint As Possible Cause For the Missing Methane In Young Exoplanets: The Case Study of V1298-Tau b