atmospheric escape Archives - Page 2 of 2 - Astrobiology

The three-dimensional MHD stellar wind solution for Barnard’s Star. Color contours represent number density values, while selected magnetic field lines are also shown. The solid white circle marks the orbit of the planet. -- astro-ph.EP

Astronomy & Telescopes, Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Habitable Zones, Mars, Status Report

Atmospheric Escape Rates from Mars – If it Orbited an Old M-Dwarf Star

by Keith CowingMarch 13, 2026March 13, 2026

Atmospheric escape is an important process that influences the evolution of planetary atmospheres. A variety of physical mechanisms can contribute to escape from an atmosphere, including thermal escape, ion escape, […]

Distribution of 339 planets in the stellar effective flux (𝑆eff) versus stellar temperature (𝑇eff) space. Red solid circles indicate the 17 planets orbiting within the EHZ, while gray points depict the remaining planets. Solar system planets are marked with purple circles. The green solid lines correspond to the inner and outer edges of the classical 1D habitable zone, as defined by Kopparapu et al. (2013). The blue dashed line represents the inner edge of the Extended Habitable Zone (EHZ) around M dwarf stars, assuming 30% heat transport efficiency (Wandel 2023a). The brown curve marks the outer edge of the EHZ, determined by the melting of ice sheets driven by geothermal heat (Wandel 2023b). The gray dashed line indicates the tidally locked radius around M dwarf stars. The green shaded region defines the classical HZ and the blue shaded region highlights the extended HZ for tidally locked exoplanets. -- astro-ph.EP

Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Gaia - Planetary Perspectives, Habitable Zones, Imaging & Spectroscopy, Status Report, Water/Hycean Worlds & Oceanography

Exploring The Habitability And Interior Composition Of Exoplanets Lying Within The Extended Habitable Zone

by Keith CowingJuly 8, 2025July 8, 2025

Studying the habitability, internal structure and composition of exoplanets is crucial for understanding their potential to sustain life beyond our solar system.

Scaled equivalent width as a function of mass-loss rate, for Jupiters, Neptunes and Sub-Neptunes.

Astrogeology, Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Status Report

Understanding What Helium Absorption Tells Us About Atmospheric Escape From Exoplanets

by Keith CowingJanuary 15, 2025January 15, 2025

Atmospheric escape is now considered the major contributing factor in shaping the demographic of detected exoplanets.

125 flares discovered in CM Draconis, stacked together and aligned to have a peak at 𝑡 = 0.

Astronomy & Telescopes, Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Proxima Centauri, Radiation, Space Weather & Heliophysics, Status Report, Stellar Cartography, TRAPPIST-1

Identifying Flare Locations Through Exoplanet Transit Occultations

by Keith CowingJanuary 11, 2025

M dwarfs are the most common stars in the galaxy, with long lifespans, a high occurrence rate of rocky planets, and close-in habitable zones.

Oxygen retention efficiency as a function of initial water content in TO. Top Row: Interior planets, T1-b, c, and d. Bottom Row: Outer planets, T1-e, f, g, and h. Coloring shows the percentage of simulations at a particular initial water content that fell in a given oxygen retention efficiency bin (e.g., each column corresponds to one initial water content and sums to 100%). Contours are given for the 50th percentile values (solid white lines) and the 1σ confidence region (dashed white lines). -- astro-ph.EP

Astrogeology, Astronomy & Telescopes, Atmospheres, Climate, Weather, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Status Report, TRAPPIST-1

The Implications of Thermal Hydrodynamic Atmospheric Escape on the TRAPPIST-1 Planets

by Keith CowingMay 7, 2024May 7, 2024

JWST observations of the 7-planet TRAPPIST-1 system will provide an excellent opportunity to test outcomes of stellar-driven evolution of terrestrial planetary atmospheres, including atmospheric escape, ocean loss and abiotic oxygen […]

Depths of the eighteen strongest lines in the transit spectra, as well as the metastable helium and calcium infrared triplet lines. The results are shown for the models with a fixed density at the planet radius (right column of Fig. 3). Our computational radial domain extends to 8Rp, corresponding to a maximum absorption of 16.9%, which is reached by various spectral lines. Lines originating from metal atoms (solid) and singly charged ions (dashed) tend to become stronger up to 10x solar metallicity, and then become weaker. Lines originating from doubly or higher charged metal ions (dotted and dash-dotted) keep growing stronger as the metallicity increases. -- astro-ph.EP

Astronomy & Telescopes, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report

The Open-source Sunbather Code: Modeling Escaping Planetary Atmospheres And Their Transit Spectra

by Keith CowingApril 24, 2024April 24, 2024

Atmospheric escape is thought to significantly influence the evolution of exoplanets, especially for sub-Jupiter planets on short orbital periods. Theoretical models predict that hydrodynamic escape could erode the atmospheres of […]

Logarithmic scale contour plots of the escaping O+ ion density (units of cm−3 ) in the meridional plane for cases with different planetary radii subjected to the same ancient solar conditions. The second plot from the left in the top row (R = 0.75 RV ) has the highest atmospheric ion escape rate. -- astro-ph.EP

Astronomy & Telescopes, Atmospheres, Climate, Weather, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Status Report

Role Of Planetary Radius on Atmospheric Escape of Rocky Exoplanets

by Keith CowingJanuary 31, 2024January 30, 2024

Large-scale characterization of exoplanetary atmospheres is on the horizon, thereby making it possible in the future to extract their statistical properties.