An exoplanet orbiting a dwarf star 124 light-years from Earth made headlines around the world in April 2025. Researchers at the University of Cambridge reported that planet K2-18b could be […]
K2-18b
Posted inExoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Status Report
Hydrocarbon Hazes On Temperate Sub-Neptune K2-18b Supported By Data From The James Webb Space Telescope
K2-18b, a sub-Neptune orbiting in the habitable zone of an M dwarf, has attracted significant interest following observations with the Hubble Space Telescope (HST) and, more recently, with the James […]
Posted inAstrogeology, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report, Water/Hycean Worlds & Oceanography
Nitrogen Chemistry Of Hycean Worlds On The Example Of K2-18b
A recent observation of the exoplanet K2-18b sparked interest among scientists – large amounts of carbon dioxide and methane were detected in an H2-rich background atmosphere.
Posted inAtmospheres, Climate, Weather, Exoplanets, -moons, -comets, Status Report
Thermoelastic Contraction As A Suppressor Of Atmospheric Escape In Close-in Exoplanets
The long-term retention of substantial atmospheres in close-in exoplanets presents a major challenge to classical hydrodynamic escape theory, which predicts rapid mass loss under intense stellar irradiation.
Posted inAstrochemistry, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Status Report
K2-18b Does Not Meet The Standards Of Evidence For Life
K2-18b, a temperate sub-Neptune, has garnered significant attention due to claims of possible biosignatures in its atmosphere. Low-confidence detections of dimethyl sulfide (DMS) and/or dimethyl disulfide (DMDS) have sparked considerable […]
Posted inAtmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Gas Giants, Habitable Zones, Ice Giant, Imaging & Spectroscopy, Status Report, TRAPPIST-1
Diversity of Rocky Planet Atmospheres In The C-H-O-N-S-Cl System With Interior Dissolution, Non-ideality, and Condensation: Application to TRAPPIST-1e and Sub-Neptunes
A quantitative understanding of the nature and composition of low-mass rocky exo(planet) atmospheres during their evolution is needed to interpret observations.
Posted inAstronomy & Telescopes, Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report
The Challenges of Detecting Gases in Exoplanet Atmospheres
Claims of detections of gases in exoplanet atmospheres often rely on comparisons between models including and excluding specific chemical species.
Posted inAstrochemistry, Atmospheres, Climate, Weather, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Press Release
Gas-phase Formation Routes Of Dimethyl Sulfide In The Interstellar Medium
Context: Dimethyl sulfide (DMS; CH3SCH3) is an organosulfur compound that has been suggested as a potential biosignature in exoplanetary atmospheres. In addition to its tentative detections toward the sub-Neptune planet […]
Posted inAstronomy & Telescopes, Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Habitable Zones, Status Report
Planetary Albedo Is Limited By The Above-cloud Atmosphere: Implications For sub-Neptune Climate (K2-18b)
Energy limits that delineate the habitable zone’ for exoplanets depend on a given exoplanet’s net planetary albedo (or Bond albedo’). We here demonstrate that the planetary albedo of an observed […]
Posted inAstrogeology, Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Status Report
TOI-6478 b: A Cold Under-dense Neptune Transiting A Fully Convective M Dwarf From The Thick Disc
Growing numbers of exoplanet detections continue to reveal the diverse nature of planetary systems. Planet formation around late-type M dwarfs is of particular interest.