Water Archives

Schematic representation of the microscopic structure of superionic water, in which the oxygen atoms form a solid crystal lattice, while hydrogen ions are virtually free to move within it. With the aid of powerful lasers, this extreme state, which otherwise only occurs inside large planets, could be measured experimentally. (Image: Greg Stewart / SLAC National Accelerator Laboratory)

Astrochemistry, Astrogeology, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Exoplanets, -moons, -comets, Gas Giants, Ice Giant, Icy Worlds, Press Release

Key To Researching Large Planets: Research Team Discovers Novel Form Of Water

by Keith CowingJanuary 14, 2026January 14, 2026

Temperatures of several thousand degrees Celsius and pressures of millions of atmospheres: superionic water only forms under extreme conditions. These conditions transform water into an unusual state in which hydrogen […]

Astrochemistry, Astrogeology, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Comets and Asteroids, Icy Worlds, Imaging & Spectroscopy, Status Report

SPHEREx Pre-Perihelion Mapping of H2O, CO2, and CO in Interstellar Object 3I/ATLAS

by Keith CowingDecember 9, 2025December 9, 2025

From 01- to 15-Aug-2025 UT, the SPHEREx spacecraft observed interstellar object 3I/ATLAS. Using R=40-130 spectrophotometry at λ=0.7-5μm, light curves, spectra, and imaging of 3I were obtained.

TOP: Heat map plots illustrating detection strength as a function of normalized exposure time and varying resolving abundance at varying Earth H2O abundances with 2 spectral points permitted at each bandwidth. lnB≥5 is a strong detection, 2.5≤lnB≤5 is a weak detection, and lnB≤2.5 is unconstrained. A modern abundance of H2O is considered to be 3×10−3 . With two spectral points regardless of bandwidth, H2O detectability is low, requiring higher abundances. BOTTOM: Heat map plots illustrating detection strength as a function of normalized exposure time and varying resolving abundance at varying Earth H2O abundances with 3 spectral points permitted at each bandwidth. lnB≥5 is a strong detection, 2.5≤lnB≤5 is a weak detection, and lnB≤2.5 is unconstrained. Note that the y-axis is cropped to 3.84, to more directly compare to Figure 2 which caps at 4.0. The key factor to photometric H2O detection is spectral point quantity. -- astro-ph.EP

Astrochemistry, Astronomy & Telescopes, Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Press Release

Determining the Detectability of H2O With Photometric Observations Using Bayesian Analysis For Remote Biosignature Identification On exoEarths (BARBIE)

by Keith CowingDecember 9, 2025December 9, 2025

We examine the detectability of water (H2O) in the reflected-light spectrum of an Earth-like exoplanet assuming a photometric observational approach rather than spectroscopic.

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 […]

Astrochemistry, Astrogeology, Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Gaia Mission, Habitable Zones, Press Release, Water/Hycean Worlds & Oceanography

Experiments Show Water Creation During Planet Formation Process

by Keith CowingNovember 3, 2025November 3, 2025

Our galaxy’s most abundant type of planet could be rich in liquid water due to formative interactions between magma oceans and primitive atmospheres during their early years, according to new […]

We show the total surface flooding for a given topography as a function of Mg/Si and FeO for a 1 M⊕ planet with Earth-like molar ratios (i.e., Fe/Mg, Ca/Mg, Al/Mg). We use cubic interpolation between data points for smoothing. The colorbar indicates the surface flooding in Earth oceans. We show the compositions of solar system planets with the following notation: Earth (⊕), Venus (♀), Mars (♂), Mercury ('), using compositional values from R. G. Trønnes et al. (2019). (A) Earth-like topography shows three distinct ”islands” correspond to the increase in water storage capacity. (B) Venus-like and (C) Mars-like topographies show similar structure in the water coverage fraction. (D) Mercury-like topography reaches complete flooding at low OM. -- astro-ph.EP

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

From Underground Oceans To Continents: A Glimpse Into The Water Inventory On Rocky Planets Using Host Star Abundances

by Keith CowingOctober 31, 2025October 31, 2025

The amount of surface water is thought to be critical for a planet’s climate stability and thus habitability.

An image depicting the transformation of a sub-Neptune exoplanet from a hydrogen-rich world into a water world. Image courtesy of Dan Shim/ASU

Astrochemistry, Astrogeology, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Icy Worlds, Press Release, Water/Hycean Worlds & Oceanography

Where Water Comes From: A New Clue From Alien Worlds

by Keith CowingOctober 30, 2025October 30, 2025

For decades, scientists believed that Earth’s water originated far from the sun. In the cold outer reaches of the solar system, water-rich bodies formed and later migrated inward, delivering water […]

This artist’s impression shows the evolution of heavy water molecules (H2O, HDO, and D2O) as they have been observed in giant molecular clouds, a planet forming-disk, and comets—before they eventually may have made their way to Earth. Credit: NSF/AUI/NSF NRAO/P. Vosteen, B. Saxton

Astrochemistry, Astrogeology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Interstellar, Press Release

First-ever Detection Of Heavy Water In A Planet-forming Disk

by Keith CowingOctober 15, 2025October 15, 2025

Astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) have made a first-ever detection of doubly deuterated water (D2O, or “heavy water”) in a planet-forming disk around V883 Ori, a young […]

Mars craterfill deposits showing varying intensities and topographies

Astrogeology, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Caves, Craters, Mountains, Subsurface, Lava Tubes, Desert Worlds, Habitable Zones, Imaging & Spectroscopy, Mapping, Geodesy, Cartography, Bathymetry, Mars, Press Release, Water/Hycean Worlds & Oceanography

Mars Crater Deposits Reveal A History Of Shrinking Ice Volumes Through Ages

by Keith CowingOctober 10, 2025October 10, 2025

For decades, scientists have been curious about how much water Mars once had and what led to its gradual transformation into the dry planet we see today.

Boundaries of the Habitable Zone. The horizontal axis marks the radiative flux relative to Earth and the vertical ones, the effective temperature and approximate spectral type of the host star (spectral type boundaries are marked by horizontal thin dashed lines). Solid green curves indicate the conservative HZ boundaries for rapidly rotating planets. Also shown is the Recent Venus inner HZ boundary (green dashed) and the Greenhouse Runaway one (light green dashed curve). The blue dashed curves represent the inner extended HZ boundary for locked planets (Wandel 2025). A global heat transport of 30% (f=0.3) and albedo of 0.3 are assumed. The curve marked “Night ice evaporation” is the moist greenhouse curve shifted to the right by a factor of 1/0.3=3.3. The curves marked “Night Moist Greenhouse” and “Night Greenhouse runaway” are the moist and runaway greenhouse curves for f=0.3 (Wandel 2025). The red curve marks the tidal locking radius (Wandel 2023b) and blue dots denote Solar System planets. -- astro-ph.EP

Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Exoplanets, -moons, -comets, Habitable Zones, Status Report

Exoplanets Beyond The Conservative Habitable Zone: II. Occurrence

by Keith CowingOctober 9, 2025

We demonstrate that the extension of the Habitable Zone (HZ) due to the presence of liquid water on the night side of tidally locked planets, modelled in this and earlier […]