Recent transit observations of K2-18b and TOI-270d revealed strong molecular absorption signatures, lending credence to the idea that temperate sub-Neptunes (Teq=250-400K) have upper atmospheres mostly free of aerosols.
TOI-270d
Posted inAtmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Icy Worlds, Imaging & Spectroscopy, Status Report, Water/Hycean Worlds & Oceanography
Examining the Potential for Methyl Halide Accumulation and Detectability in Possible Hycean-Type Atmospheres
Some sub-Neptune planets may host habitable conditions; for example “Hycean” worlds with H2 envelopes over liquid water oceans can maintain potentially hospitable pressures and temperatures at their surface.
Posted inAstrochemistry, Astrogeology, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Exoplanets, -moons, -comets, Habitable Zones, Icy Worlds, Status Report, Water/Hycean Worlds & Oceanography
Planets Contain More Water Than Previously Thought
Most of a planet’s water is generally not found on the surface, but is hidden deep inside. This affects the potential habitability of distant worlds, as model calculations by researchers […]