Water/Hycean Worlds & Oceanography Archives

Outgoing thermal emission as a function of surface temperature. The dashed-dotted line is the classic runaway curve obtained with fully convective profiles, independently from the stellar radiation spectrum and internal flux. With self-consistent profiles, this function depends on the type of the host star and the internal flux ϕint. Dashed curves are obtained with Earth geothermal flux. For T-1 and ϕint < 0.01 Wm−2 , the runaway greenhouse can end without full vaporization of the ocean. Low-pressure liquidus, solidus and melting (melt fraction = 40%) temperatures are indicated for an Earth mantle composition. Surface pressure is 270 bars except in the blue area where Tsurf is below the critical temperature of H2O and psurf is given by the saturation vapor pressure of H2O. These curves are based on the profiles shown in Extended Data Figure 2 -- astro-ph.EP

Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Lava / magma ocean / Volcanic Worlds, Status Report, Water/Hycean Worlds & Oceanography

A Cool Runaway Greenhouse Without Surface Magma Ocean

by Keith CowingNovember 17, 2023May 11, 2024

Water vapour atmospheres with content equivalent to the Earth’s oceans, resulting from impacts or a high insolation, were found to yield a surface magma ocean. This was, however, a consequence […]

Illustration of Earth’s interior revealing subducting water and a rising plume of magma. At the interface where subducting water meets the core, a chemical exchange occurs to form a hydrogen-rich layer in the topmost outer core and dense silica in the bottom of the mantle. Image courtesy Yonsei University

Astrogeology, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Press Release, Water/Hycean Worlds & Oceanography

Surface Water Dives Deep And Transforms Earth’s Core’s Outer Layer

by Keith CowingNovember 15, 2023November 15, 2023

A few decades ago, seismologists imaging the deep planet identified a thin layer, just over a few hundred kilometers thick. The origin of this layer, known as the E prime […]

Galena crystals with siderite and greenalite from San Valentín open pit, Cartagena, Spain. - Wikipedia

Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Fossils & Paleontology, Origin & Evolution of Life, Press Release, Water/Hycean Worlds & Oceanography

Recreation Of Ancient Seawater Reveals Which Nutrients Shaped The Evolution Of Early Life

by Keith CowingNovember 14, 2023November 14, 2023

Scientists know very little about conditions in the ocean when life first evolved, but new research published in Nature Geoscience has revealed how geological processes controlled which nutrients were available […]

ROV SuBastian takes water and chemical samples from a black smoker hydrothermal vent in the Iguanas Vent Field, Galapagos Islands. Iguanas Vent Field, Galapagos Islands (Image made at 1650.23 meters depth).

Away Teams & Field Reports, Exploration Gear & Tech, Extremeophiles and Extreme Environments, Habitable Zones, Mapping, Geodesy, Cartography, Bathymetry, Missions & Hardware, Press Release, ROVs/Submersibles/Diving, Water/Hycean Worlds & Oceanography

New Hydrothermal Vent Found In The Iguanas Vent Field, Galapagos Islands

by Keith CowingNovember 12, 2023November 12, 2023

Scientists on a Schmidt Ocean Institute expedition have discovered a new hydrothermal vent field larger than a professional soccer field. The vent field found in the Pacific Ocean off the […]

a Surface elevation of the Antarctic Ice Sheet from the Reference Elevation Model of Antarctica68. The black line marks the present-day grounding line74; pale areas are floating ice shelves. b Bed elevation of Antarctica beneath the grounded ice sheet from BedMachine v.364. Surface and bed elevations are relative to the global mean sea level (the EIGEN-6C4 geoid). The black dashed box shows the extent of the maps in Figs. 2 and 5, and lines of latitude are separated by 5°. ASB Aurora Subglacial Basin, DML Dronning Maud Land, GSM Gamburtsev Subglacial Mountains, TAM Transantarctic Mountains, WSB Wilkes Subglacial Basin. c Composite global oxygen isotope record from benthic foraminifera75. Lower (more negative) δ18O values indicate lower ice volume and/or warmer ocean temperatures; higher (more positive) δ18O values indicate greater ice volume and/or cooler ocean temperatures. Labels show the timings of major climate intervals or transitions (red), glacial expansions (black), and prevailing glacial conditions (blue). Plio. = Pliocene; Plt. = Pleistocene; note that the Holocene epoch (0.012–0 Ma) is not shown on the timescale. -- Science

Analog Studies, Arctic / Antarctic / Alpine, Astrogeology, Icy Worlds, Mapping, Geodesy, Cartography, Bathymetry, Press Release, Water/Hycean Worlds & Oceanography

Ancient Landscape Discovered Beneath The East Antarctic Ice Sheet

by Keith CowingNovember 11, 2023November 11, 2023

Editor’s note: of particular interest to Astrobiology mission planners are the ice-covered worlds in our solar system – Enceladus, Europa, Ganymede, Mimas, Titan, etc. and the probability that they have […]

Boundaries of the Habitable Zone under various climate and atmospheric models as a function of radiative flux received from the host star, relative to Earth. Dashed lines represent the extended boundaries due to subglacial liquid water suggested in this work: blue for the inner HZ boundary (nightside ice evaporates due to heat transport, the percentage marks the global transport parameter f) and violet for the outer one (Martian polar lakes). Solid green lines and green shading denote the conservative HZ boundaries: inner one (moist greenhouse) and outer one (maximum CO2 greenhouse), calculated using the 1-D climate model. Also marked is the recent Venus boundary (dashed green line). The orange curve marks the tidal locking radius. Circles denote the terrestrial planets in the solar system and a few Earth-sized exoplanets orbiting M-dwarf stars. -- Hebrew University of Jerusalem

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

Extended Habitability Of Exoplanets Due To Subglacial Water

by Keith CowingNovember 10, 2023November 10, 2023

Professor Amri Wandel, from Hebrew University of Jerusalem, has unveiled research that promises to redefine our comprehension of habitable exoplanets. In a recent study published in the Astronomical Journal, Professor […]

This enhanced image of the Jovian moon Ganymede was obtained by the JunoCam imager aboard NASA's Juno spacecraft during the mission's June 7, 2021, flyby of the icy moon on Juno's 34th pass close to Jupiter. This is an extended, upscaled and artistically enhanced version of a previously released JunoCam image: PIA24681. larger image

Biosignatures & Paleobiology, Ganymede, Icy Worlds, Imaging & Spectroscopy, Press Release, Water/Hycean Worlds & Oceanography

Salts and Organics Observed on Ganymede’s Surface

by Keith CowingOctober 30, 2023October 30, 2023

Data collected by NASA’s Juno mission indicates a briny past may be bubbling to the surface on Jupiter’s largest moon.

Results of Global Climate Model (GCM) simulations of LHS 1140 b assuming an Earth-like atmosphere (1 bar N2, 400 ppm CO2; panels a, c, d, e) and a thick CO2-dominated atmosphere (5 bar CO2; panels b, f, g, h). Panels a, b: Surface temperature maps of LHS 1140 b. The black line indicates the line of stability between liquid water and sea ice. The extent of the ice-free ocean strongly depends on the amount of CO2 in the atmosphere. Panels c, d, e, f, g, and h: Vertical profiles of the atmospheric temperatures, water vapor, and cloud mixing ratios (both H2O and CO2 ice clouds). The solid bold lines indicate the global mean vertical profiles and the dotted lines indicate terminator vertical profiles (impacting transit spectra). -- astro-ph.EP

Astronomy & Telescopes, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report, Water/Hycean Worlds & Oceanography

New Mass and Radius Constraints On The LHS 1140 Planets — LHS 1140 b Is Either A Temperate Mini-Neptune Or A Water World

by Keith CowingOctober 30, 2023October 30, 2023

LHS 1140 b and c are two small temperate exoplanets transiting a nearby M4.5 dwarf. The planetary system was observed with multiple facilities since its discovery in 2017, including MEarth, […]

Mass-radius diagram showing confirmed planets with mass uncertainties < 20% in grey circles, with TOI-544 b shown as the black circle. Left: the coloured tracks show different potential planet compositions from Zeng et al. (2019), assuming a planetary equilibrium temperature of 1000 K. The dashed lines show compositions of an Earth-like rocky core surrounded by a layer of H-He in varying percentages by mass, the solid lines show water world compositions with varying water mass fractions, the dotted lines show rocky and Earth-like rocky compositions. TOI-544 b is closest to the tracks with 100% H2O and 50% H2O with 50% rock. Right: the same as the left panel but the the dashed lines show compositions of an Earth-like rocky core surrounded by a layer of H-He in varying percentages by mass from Lopez & Fortney (2014) using the models for a 10Gyr planet, with solar metalicity and flux of 10F⊕, the solid lines show compositions from Aguichine et al. (2021) of irradiated ocean worlds with varying water mass fractions, and the dotted lines show the same rocky and Earth-like rocky compositions from Zeng et al. (2019). TOI-544 b is closest to models with either 30% water mass fraction, or a rocky core with a Hydrogen envelope of between 0.5 - 1%. The data is downloaded from the NASA Exoplanet Archive. -- astro-ph.EP

Astronomy & Telescopes, Atmospheres, Climate, Weather, Biosignatures & Paleobiology, Exploration Gear & Tech, Habitable Zones, Icy Worlds, Imaging & Spectroscopy, Status Report, Water/Hycean Worlds & Oceanography

TOI-544 b: A Potential Water-world Inside The Radius Valley In A Two-planet System

by Keith CowingOctober 24, 2023October 24, 2023

We report on the precise radial velocity follow-up of TOI-544 (HD 290498), a bright K star (V=10.8), which hosts a small transiting planet recently discovered by the Transiting Exoplanet Survey […]

Illustration of our strategy to detect habitable exoplanetary environment via CO2 depletion. Each of the planets to the right hand side of the star describes a different scenario discussed in the text (along with illustrative atmospheric concentrations). The panel on the left hand side depicts a simulation of the transmission spectrum of the temperate terrestrial planet TRAPPIST-1 f. We explore the detectability of an atmosphere with ∼ 10 JWST/NIRSpec Prism transit observations, the minimum needed to produce a reliable diagnostic. Note that the deviation from a flat signal (no atmosphere) is primarily supported by the strong absorption features of CO2, notably at 4.3 µm (highlighted). Exo-atmospheric models from 142 were used to make that panel. On the lower right hand side, we illustrate a simplified view of a carbon cycle involving surface liquid water and biology sequestering cycle and producing a depletion in atmospheric carbon. Atmospheric concentrations given near the planets are illustrative. astro-ph.EP

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

Atmospheric Carbon Depletion As A Tracer Of Water Oceans And Biomass On Temperate Terrestrial Exoplanets

by Keith CowingOctober 24, 2023October 24, 2023

The conventional observables to identify a habitable or inhabited environment in exoplanets, such as an ocean glint or abundant atmospheric O2, will be challenging to detect with present or upcoming […]

Water/Hycean Worlds & Oceanography

A Cool Runaway Greenhouse Without Surface Magma Ocean

Surface Water Dives Deep And Transforms Earth’s Core’s Outer Layer

Recreation Of Ancient Seawater Reveals Which Nutrients Shaped The Evolution Of Early Life

New Hydrothermal Vent Found In The Iguanas Vent Field, Galapagos Islands

Ancient Landscape Discovered Beneath The East Antarctic Ice Sheet

Extended Habitability Of Exoplanets Due To Subglacial Water

Salts and Organics Observed on Ganymede’s Surface

New Mass and Radius Constraints On The LHS 1140 Planets — LHS 1140 b Is Either A Temperate Mini-Neptune Or A Water World

TOI-544 b: A Potential Water-world Inside The Radius Valley In A Two-planet System

Atmospheric Carbon Depletion As A Tracer Of Water Oceans And Biomass On Temperate Terrestrial Exoplanets

The Pandora SmallSat: Target Selection and Early Science

System-evolutionary View Of RNA Presence In Living Cells

The Unresolved Paradox of Viable Microorganisms in Ancient Halite

How Fluctuations Control Chiral Symmetry Breaking in Reacting Mixtures of Chiral Molecules

Early-career Graduate Students Host An Exclusive, NASA-funded Astrobiology Conference