hydrosphere Archives

Image of Mars and its thin atmosphere, photographed by Emirates Mars Mission via Wikipedia -- UAESA/MBRSC/HopeMarsMission/EXI/AndreaLuck -- larger image

The Search for Life and Biosignatures on Mars: A Mars System Science Approach (Atmosphere, Hydrosphere, Cryosphere, Lithosphere, Geologic History)

by Keith CowingAugust 11, 2026August 11, 2026

[Astrobiology (Journal)] The most important quest in Mars exploration is the search for biosignatures. We adopt a Mars System Science approach, calling on information from the atmosphere, hydrosphere, cryosphere, lithosphere, […]

Artist’s impression showing possible choices for the scale of human involvement in the future of Mars.

Atmospheres, Climate, Weather, Beta Pictoris, Biosignatures & Paleobiology, Desert Worlds, Gaia - Planetary Perspectives, Mars, Status Report, Terraforming & Geoengineering, Water/Hycean Worlds & Oceanography

A Research Roadmap For Assessing The Feasibility Of Warming Mars

by Keith CowingApril 3, 2026April 3, 2026

This roadmap outlines research pathways to determine whether Mars could be warmed with non-biological methods. It does not presuppose that warming Mars is desirable; its purpose is to identify what […]

A schematic illustration of the evolution of the Earth System

Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Gaia - Planetary Perspectives, Habitable Zones, Status Report, Water/Hycean Worlds & Oceanography

Setting Up The Physical Principles Of Resilience In A Model Of The Earth System

by Keith CowingJanuary 18, 2026January 18, 2026

Resilience is a property of social, ecological, social-ecological and biophysical systems. It describes the capacity of a system to cope with, adapt to and innovate in response to a changing […]

3D rendering of meteorite and clasts. a) 3D rendering of the attenuation tomograms cut in half in z to show two H-Fe-ox clasts, showing neutron attenuation on the left and X-ray attenuation on the right. White means high attenuation, dark means low attenuation. b) 3D rendering of segmented phases throughout the meteorite, with H-rich Fe-oxyhydroxides in blue and H-poor Fe-Ti oxides in red. c) 3D rendering of the three biggest H-Fe-ox clasts. -- astro-ph.EP

Astrogeology, Biogeochemical Cycles & Geobiology, Habitable Zones, Mars, Meteorites & Asteroids, Sample Return, Status Report, Water/Hycean Worlds & Oceanography

Direct Detection Of Hydrogen Reveals A New Macroscopic Crustal Water Reservoir On Early Mars

by Keith CowingJanuary 15, 2026January 15, 2026

The next great leap in Martian exploration will be the return of samples to Earth. To ensure the maximum scientific return from studying these samples, the development and utilisation of […]

One set of images taken by Huygens is pictured here showing the view from 2 km altitude. It is in Mercator projection, so the N–S/E–W directions cross at right angles but surface areas appear distorted. Sky above horizon is modfied for formatting.- ESA/Astrobiology.com Original image

Astrogeology, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Icy Worlds, Imaging & Spectroscopy, Saturn, Status Report, Titan, Water/Hycean Worlds & Oceanography

Absence Of A Subsurface Ocean On Titan Indicated By Cassini Data

by Keith CowingJanuary 7, 2026January 7, 2026

The Cassini spacecraft orbited Saturn from 2004 to 2017, performing over a hundred flybys of Titan, Saturn’s largest moon.

Left, the free fluids phase and Fe-enriched blebs are entrained in the magma ocean. Center: water is outgassed to create a steam atmosphere while the Fe-enriched blebs sink toward the center. Right: extreme scenario in which all phases are miscible. -- astro-ph.EP

Astrochemistry, Astrogeology, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Status Report, Water/Hycean Worlds & Oceanography

Experiments Reveal Extreme Water Generation During Planet Formation

by Keith CowingNovember 10, 2025November 10, 2025

The most abundant type of planet discovered in the Galaxy has no analogue in our Solar System and is believed to consist of a rocky interior with an overlying thick […]

Snapshots of VGS-calculated surface water mass (in units of Earth’s ocean mass) for TRAPPIST-1 analogs, shown as a function of total planet mass (M⊕) and final orbital distance (AU). Panel (a) depict planets at the halfway point of accretion (i.e., when the protoplanet reaches half its final mass), while panels (b) show the final planet properties. Measured properties of the TRAPPIST-1 planets are indicated by black circles (Agol et al. 2021). At mid-assembly, most inner planets are water-poor due to early impact-driven loss and higher irradiation. By the end of accretion, increased volatile delivery events from more water-rich materials and reduced erosion allow many planets, particularly beyond ∼0.03 AU,to accumulate and preserve large water reservoirs, leading to the strong radial gradient in water content. -- astro-ph.EP

Analog Studies, Astrochemistry, Astrogeology, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Icy Worlds, Imaging & Spectroscopy, Status Report, TRAPPIST-1, Water/Hycean Worlds & Oceanography

Born Dry or Born Wet? A Palette of Water Growth Histories in TRAPPIST-1 Analogs and Compact Planetary Systems

by Keith CowingOctober 15, 2025October 15, 2025

It is still unclear whether exoplanets in compact multiplanet systems such as TRAPPIST-1 are able to accrete large quantities of volatiles, grow to sufficient mass, and maintain robust atmospheres and […]

Ice sheet topography computed by GRISLI (step RGRGRG). For this particular simulation, the ice sheet reaches the ocean and could potentially produce icebergs. The altitude here includes the isostasy that can reach up to 800 m. The ice accumulation and ice sheet flow smooth out the surface but the largest peaks are still present in the topography. -- JGR Planets

Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Desert Worlds, Habitable Zones, Icy Worlds, Imaging & Spectroscopy, Mapping, Geodesy, Cartography, Bathymetry, Mars, Status Report, Water/Hycean Worlds & Oceanography

Ancient Mars Climate With a Polar Ocean and Ice Sheet Dynamics

by Keith CowingOctober 14, 2025October 14, 2025

In this article, we study the conditions required to maintain a stable ocean on Mars 3 Ga using a new suite of simulations.

Optical microscopy image of the clastic matrix region in LAR 12252 that was studied using S-XANES. Notable phases include enstatite (examples outlined in red), sulphides (example outlined in yellow), a small chondrule fragment (outlined in orange), and fine matrix (examples highlighted in pink). b Corresponding map calculated from the S-XANES spectra of the region shown in a, showing the amplitude of the H-S peak at each point normalised to the average amplitude of point spectra measured from chondrule mesostasis (Fig. S8). Black pixels correspond to points where the SXANES spectra that did not contain a resolvable H-S peak. White pixels correspond to points where the S-XANES spectra could not be fitted due to their quality or noise in the spectra. Some grain outlines have been transferred onto Fig 2b to allow for comparison of the two figures. -- astro-ph.EP

Astrochemistry, Astrogeology, Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biophysics, Biosignatures & Paleobiology, Habitable Zones, Impact events, Meteorites & Asteroids, Origin & Evolution of Life, Status Report, Water/Hycean Worlds & Oceanography

The Source Of Hydrogen In Earth’s Building Blocks

by Keith CowingJune 2, 2025June 2, 2025

Despite being pivotal to the habitability of our planet, the process by which Earth gained its present-day hydrogen budget is unclear.

Model scheme representation. The model represents the dissolution of volatiles from the primordial atmosphere into the ocean. The liquid-vapor equilibrium of the volatile species is coupled to a chemical equilibrium model that considers the speciation of H2O, CO2, and NH3. This coupled approach allows the partitioning of the volatiles between the atmosphere and the ocean to be determined, taking into account both physical and chemical equilibrium. This model does not account for water-rock interactions between the ocean and silicate mantle. -- astro-ph.EP

Astrogeology, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Europa, Habitable Zones, Icy Worlds, Status Report, Water/Hycean Worlds & Oceanography

The Role Of Ammonia In The Distribution Of Volatiles In The Primordial Hydrosphere Of Europa

by Keith CowingDecember 2, 2024December 2, 2024

The presence of a hydrosphere on Europa raises questions about its habitability, and studies of its volatile inventory can provide insight into its formation process. Different scenarios suggest that Europa’s […]

hydrosphere

The Search for Life and Biosignatures on Mars: A Mars System Science Approach (Atmosphere, Hydrosphere, Cryosphere, Lithosphere, Geologic History)

A Research Roadmap For Assessing The Feasibility Of Warming Mars

Setting Up The Physical Principles Of Resilience In A Model Of The Earth System

Direct Detection Of Hydrogen Reveals A New Macroscopic Crustal Water Reservoir On Early Mars

Absence Of A Subsurface Ocean On Titan Indicated By Cassini Data

Experiments Reveal Extreme Water Generation During Planet Formation

Born Dry or Born Wet? A Palette of Water Growth Histories in TRAPPIST-1 Analogs and Compact Planetary Systems

Ancient Mars Climate With a Polar Ocean and Ice Sheet Dynamics

The Source Of Hydrogen In Earth’s Building Blocks

The Role Of Ammonia In The Distribution Of Volatiles In The Primordial Hydrosphere Of Europa

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