water world Archives - Page 7 of 14 - Astrobiology

Earth's atmosphere -- NASA

Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Habitable Zones, Icy Worlds, Status Report, Water/Hycean Worlds & Oceanography

On The Relative Humidity Of Earth’s Atmosphere

by Keith CowingJuly 17, 2025July 17, 2025

Water vapour is highly subsaturated in much of the Earth’s atmosphere. This has important consequences for water vapour feedback, and also for general phenomena such as the runaway greenhouse.

The glass sponge, Advhena magnifica, prior to being collected in 2016 at a depth of ~2,000 meters (6,560 feet). Scientists call this class of sponges “glass” because their skeletons are made of silica (glass). Their bodies contain fascinating tissues that consist of many nuclei within a single membrane, and these tissues help conduct electrical signals across the sponge making them able to respond quickly to external stimuli. Image courtesy of the NOAA Office of Ocean Exploration and Research, 2016 Deepwater Exploration of the Marianas.

Away Teams & Field Reports, Biosignatures & Paleobiology, Exploration Gear & Tech, Fossils & Paleontology, Mapping, Geodesy, Cartography, Bathymetry, Nomenclature, Systematics, Natural History, Press Release, Robotics/Rovers/UAVs, ROVs/Submersibles/Diving, Sample Return, Science Fiction, Water/Hycean Worlds & Oceanography

Ocean Planet Exploration And Taxonomy: Naming A Strange New Species

by Keith CowingJuly 14, 2025July 14, 2025

Editor’s note: one day we will begin a detailed exploration of ocean worlds other than our own. Hopefully they will be habitable – and inhabited. Given that we still find […]

The instantaneous Vtid on Proxima b at periastron (a) and at apastron (b), and the orbital-mean amplitude of tidal potential (Vtid) on Proxima b (c) and on Earth (d). -- astro-ph.EP

Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Exoplanets, -moons, -comets, Habitable Zones, Status Report, Water/Hycean Worlds & Oceanography

Ocean Tides On Asynchronously Rotating Planets Orbiting Low-mass Stars

by Keith CowingJuly 12, 2025July 12, 2025

Planets in the liquid-water habitable zone of low-mass stars experience large tidal forces, 103 to 104 times those on Earth, due to the small distance between the habitable zone and […]

(a) Galileo Solid State Imaging (SSI) false color data of Europa’s leading hemisphere and Tara Regio (credit: NASA, JPL/Caltech, PIA01295). (b) Illustration of chaos on Europa (credit: NASA, GSFC, PIA00840), showing hypothesized geologic communication between its subsurface ocean and surface (chaos formation mechanisms summarized in e.g., Daubar et al. 2024). (c) Spectral map showing the distribution of irradiated NaCl on Europa, highlighting its concentration in and around Tara Regio (modified from Trumbo et al. 2019). -- astro-ph.IM

Ariel, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Ceres, Enceladus, Europa, Habitable Zones, Icy Worlds, Status Report, Water/Hycean Worlds & Oceanography

Assessing Ocean World Habitability With HWO

by Keith CowingJuly 11, 2025July 11, 2025

The instrument payload of the future Habitable Worlds Observatory (HWO) will span a wide range of wavelengths, including the ultraviolet (UV) region that cannot be easily accessed from the ground […]

A schematic of four observing programs (science cases) proposed in this HWO science case to discover and characterize life beyond Earth. -- astro-ph.EP

Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Gaia - Planetary Perspectives, Habitable Zones, Imaging & Spectroscopy, Origin & Evolution of Life, Plant Biology, Press Release, Water/Hycean Worlds & Oceanography

Detecting Alien Living Worlds And Photosynthetic Life Using Imaging Polarimetry With The HWO Coronagraph

by Keith CowingJuly 8, 2025July 8, 2025

Our Earth, being the only living planet that we know, provides us with clues that photosynthetic life-forms may be dominant on other exoplanets for billions of years.

Planetary reflectivity (top; total flux) and polarization (bottom; polarized flux) as a function of scattering angle (or phase angle) and wavelength (colors). Glories, rainbows, Rayleigh scattering, and ocean glint generate strong polarization signatures and subtle reflectance signatures. (Figure from Vaughan et al. 2023). -- astro-ph.IM

Astronomy & Telescopes, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Status Report, Water/Hycean Worlds & Oceanography

Detecting Surface Liquid Water On Exoplanets

by Keith CowingJuly 8, 2025July 8, 2025

Planets with large bodies of water on their surface will have more temperate and stable climates, and such planets are the ideal places for life-as-we-know-it to arise and evolve.

Modelled planetary bulk-density over time. The initial hydrogen inventory of each bulk-density evolution track is shown by the line colour. Blue/green shaded regions are reference densities for a planet of this mass (Zeng et al., 2019). Black dashed/dotted lines demarcate edges of the radius valley (at this planet mass) for low mass stars (Ho et al., 2024). The region ±1σ compatible with the estimated bulk-density of this planet is indicated by the blue errorbar (Rajpaul et al., 2024; Demangeon et al., 2021). Top panel: evolution of surface temperature (coloured) and stellar XUV energy flux (black). For visual clarity, this figure only shows cases with S/H=8. -- astro-ph.EP

Exoplanets, -moons, -comets, Status Report

Volatile-rich Evolution Of Molten Super-Earth L 98-59 d

by Keith CowingJuly 7, 2025September 18, 2025

Small low-density exoplanets are sculpted by strong stellar irradiation but their origin is unknown.

Hydrothermal Systems May Have Supplied Essential Phosphorus For Early Life -- Tohoku University

Astrochemistry, Astrogeology, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biophysics, Biosignatures & Paleobiology, Extremeophiles and Extreme Environments, Habitable Zones, Origin & Evolution of Life, Press Release

Hydrothermal Systems May Have Supplied Essential Phosphorus For Early Life

by Keith CowingJuly 4, 2025July 4, 2025

Understanding where and in what quantities essential elements for life have existed on Earth’s surface helps explain the origin and evolution of life. Phosphorus (P) is one such element, forming […]

Envelope H2O mass fraction as a function of semi-major axis. The same dataset as in Figure 1 is shown. The left panel shows planets that predominantly formed inside the water ice line; the right panel shows those that formed outside. Classification is based on the accreted H2O mass fraction, with a threshold set at 5% of the total planetary mass. The colorbar indicates the molar bulk C/O ratio. Planets formed inside the ice line are systematically depleted in carbon due to the lack of volatile ice accretion and exhibit higher envelope H2O mass fractions. In contrast, planets formed beyond the ice line retain lower H2O content despite higher bulk volatile abundances. Each pie chart shows the mean mass fraction of hydrogen in H2 (gas), H (metal), H2 (silicate), H2O (gas), and H2O (silicate), normalized to the total mean hydrogen inventory for each population. Only components contributing more than 5% are labeled. Planets that formed beyond the ice line store most hydrogen as H2 (gas) and H (metal), while those that formed inside the ice line retain a larger share of hydrogen in H (metal) H2 (silicate) and H2O (gas + silicate). -- astro-ph.EP

Astrochemistry, Astrogeology, Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Ice Giant, Icy Worlds, Status Report, Water/Hycean Worlds & Oceanography

Sub-Neptunes Are Drier Than They Seem: Rethinking the Origins of Water-Rich Worlds

by Keith CowingJuly 3, 2025July 3, 2025

Recent claims of biosignature gases in sub-Neptune atmospheres have renewed interest in water-rich sub-Neptunes with surface oceans, often referred to as Hycean planets.

Autonomous Underwater Vehicle -- University of Sydney

Away Teams & Field Reports, Exploration Gear & Tech, Imaging & Spectroscopy, Mapping, Geodesy, Cartography, Bathymetry, Press Release, Robotics/Rovers/UAVs, ROVs/Submersibles/Diving, Sample Return, Water/Hycean Worlds & Oceanography

Ocean Planet Expedition: Robots Map Unexplored Depths

by Keith CowingJune 23, 2025June 23, 2025

Autonomous Underwater Vehicles (AUV) from the University of Sydney has taken a deep dive in the oceans surrounding Norfolk Island on an scientific expedition to document previously unexplored reefs.