Gaia Archives

Nicholas Ray, assistant professor in the School of Marine Science and Policy at the University of Delawarew, was part of a National Science Foundation research coordination network that released a paper focused on nitrogen fixation in freshwater and coastal ecosystems. Here, he conducts the lab work for one method of measuring sediment-water N2 fluxes (including N-fixation). Credit Photos courtesy of Nicholas Ray/ University of Delaware

Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Gaia - Planetary Perspectives, Microbiology & Virology, Press Release, Sample Return, Water/Hycean Worlds & Oceanography

Small Aquatic Systems Found To Fix 15% Of Earth’s Nitrogen

by Keith CowingNovember 9, 2025November 9, 2025

Nitrogen is vital for all known life. Yet most nitrogen on Earth is in the atmosphere as di-nitrogen gas, which many organisms can’t use. Fortunately, there are microbes that can […]

Biogeochemical Cycles & Geobiology, Desert Worlds, Gaia - Planetary Perspectives, Habitable Zones, Mars, Status Report, Terraforming & Geoengineering

An Introduction To Mars Terraforming – 2025 Workshop Summary

by Keith CowingOctober 22, 2025October 22, 2025

Terraforming Mars is an age old science fiction concept now worth revisiting through the lens of modern science and technology. This document serves as a summary of contemporary ideas about […]

[L] Latitude-longitude maps of surface temperature overlaid with the wind field at the bottom layer, and surface precipitation. The black contours indicate where the surface temperature is 50◦ Celsius. [R] Latitude-longitude maps of surface temperature overlaid with the wind field at the bottom layer, and surface precipitation, for ISR = 1580 Wm−2 , which brings the climate to the onset of a runaway greenhouse effect. The minimum surface temperature between the two surface albedo cases is 345 K or 72◦C.Latitude-longitude maps of surface temperature overlaid with the wind field at the bottom layer, and surface precipitation, for ISR = 1580 Wm−2 , which brings the climate to the onset of a runaway greenhouse effect. The minimum surface temperature between the two surface albedo cases is 345 K or 72◦C. -- astro-ph.EP

Astronomy & Telescopes, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Status Report

Near The Runaway: The Climate And Habitability Of Teegarden’s Star b

by Keith CowingOctober 15, 2025October 15, 2025

Teegarden’s Star b, a nearby terrestrial world receiving an Earth-like instellation, is a prime candidate for next-generation observatories targeting temperate exoplanets in their habitable zones.

Conceptual model for the evolution of exoenzymes and the recycling of organic matter across the Great Oxidation Event (GOE). (A) In the Archean Ocean, prior to the GOE, the recycling of organic matter depended entirely on the activity of fermenters. This resulted in low recycling efficiency, elevated carbon burial, and limited regeneration of essential nutrients back into seawater. This scarcity of particulate organic matter (POM) also reduced the availability of niches for microbial colonization, thus limiting the selective pressure for the evolution of exoenzyme systems. (b) Following the GOE, rising oxygen levels increased the availability of high-energy electron acceptors (e.g. O2, nitrate and ferric iron), supporting the expansion of metabolic groups with high exoenzyme capacity, such as aerobic heterotrophs, dissimilatory nitrate reducers and dissimilatory ferric iron reducers. Concurrently, increases in POM abundance and microbial cell densities would have amplified the selective pressure to produce exoenzymes. Collectively, these changes in the Paleoproterozoic promoted more efficient recycling of organic matter and regeneration of nutrients back into the water column, ultimately fueling greater primary productivity and oxygen release. This feedback between exoenzyme evolution, nutrient cycling, and oxygen production would have amplified Earth’s progressive oxygenation. -- biorxiv.org

Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biophysics, Biosignatures & Paleobiology, Gaia - Planetary Perspectives, Origin & Evolution of Life, Status Report, Water/Hycean Worlds & Oceanography

Microbial Exoenzymes Catalyzed The Transition To An Oxygenated Earth

by Keith CowingOctober 11, 2025October 11, 2025

Microbial exoenzymes—extracellular enzymes secreted to degrade complex organic polymers— are essential for recycling carbon and nutrients, thus sustaining primary productivity in today’s oceans.

Using a microscope inside a research lab on Mars - Grok via Astrobiology.com

Astrobiology (general), Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Gaia - Planetary Perspectives, Microbiology & Virology, Space Life Science, Status Report, Terraforming & Geoengineering, Water/Hycean Worlds & Oceanography

Planetary Microbiology: Microbes, Planets, And The Search For Life

by Keith CowingOctober 4, 2025October 4, 2025

Life on Earth has been shaped by transformative microbial innovations and singularities that redefined planetary systems, from oxygenic photosynthesis to biological nitrogen fixation.

Exoplanets, -moons, -comets, Gaia - Planetary Perspectives, Habitable Zones, Status Report

Other Earths, Gaian bottlenecks and Darwinized Gaias

by Keith CowingSeptember 29, 2025September 29, 2025

In our galaxy, tens of billions of wet, rocky Earth-like planets orbit in the habitable zones of their host stars.

NASA’s Solar Dynamics Observatory captured this image of an X1.5 solar flare peaking at 7:44 am EDT on May 11, 2024. The image shows a subset of extreme ultraviolet light that highlights the extremely hot material in flares created from a mixture of SDO’s AIA 193, 171 and 131 channels. -- larger image NASA

Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Gaia - Planetary Perspectives, Press Release, Radiation, Space Weather & Heliophysics

As Earth’s Atmosphere Changes, So Will Its Response To Geomagnetic Storms

by Keith CowingAugust 17, 2025

Rising concentrations of carbon dioxide in the upper atmosphere will change the way geomagnetic storms impact Earth, with potential implications for thousands of orbiting satellites, according to new research led […]

Graphical Abstract -- Bar-Ilan University

Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biophysics, Extremeophiles and Extreme Environments, Gaia - Planetary Perspectives, Habitable Zones, Mapping, Geodesy, Cartography, Bathymetry, Microbiology & Virology, Status Report, Water/Hycean Worlds & Oceanography

RNA Viruses May Differentially Shape Carbon Recycling In The Ocean

by Keith CowingJuly 17, 2025July 17, 2025

A new study by researchers at Bar-Ilan University has uncovered that certain ocean viruses—specifically RNA viruses—may disrupt how carbon and nutrients are recycled in the ocean, potentially altering the global […]

Distribution of 339 planets in the stellar effective flux (𝑆eff) versus stellar temperature (𝑇eff) space. Red solid circles indicate the 17 planets orbiting within the EHZ, while gray points depict the remaining planets. Solar system planets are marked with purple circles. The green solid lines correspond to the inner and outer edges of the classical 1D habitable zone, as defined by Kopparapu et al. (2013). The blue dashed line represents the inner edge of the Extended Habitable Zone (EHZ) around M dwarf stars, assuming 30% heat transport efficiency (Wandel 2023a). The brown curve marks the outer edge of the EHZ, determined by the melting of ice sheets driven by geothermal heat (Wandel 2023b). The gray dashed line indicates the tidally locked radius around M dwarf stars. The green shaded region defines the classical HZ and the blue shaded region highlights the extended HZ for tidally locked exoplanets. -- astro-ph.EP

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

Exploring The Habitability And Interior Composition Of Exoplanets Lying Within The Extended Habitable Zone

by Keith CowingJuly 8, 2025July 8, 2025

Studying the habitability, internal structure and composition of exoplanets is crucial for understanding their potential to sustain life beyond our solar system.

Reef scene off the coast of St. Croix, USVI [Photo credit: NOAA CCMA Biogeography Branch]

Away Teams & Field Reports, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Gaia - Planetary Perspectives, Habitable Zones, Mapping, Geodesy, Cartography, Bathymetry, Press Release, Water/Hycean Worlds & Oceanography

How Earth’s Biomass Changed Over 500 Million Years

by Keith CowingJuly 6, 2025July 6, 2025

In a first-of-its-kind study, Stanford researchers have measured how the abundance of ocean life has changed over the past half-billion years of Earth’s history.