Results 251 to 260 of about 15,535 (284)

Escaping atmospheres of extrasolar planets

Science, 2018
The study of helium absorption opens a new window on escaping exo ...
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Escape of Planetary Atmospheres. I. Escape Layer

The Physics of Fluids, 1961
The critical layer for thermal escape of a planetary atmosphere is treated on a model in which an isothermal exosphere at high temperature merges within a narrow zone (the endopause) of varying temperature into the remainder (the endosphere) of the atmosphere, isothermal above the level at which mixing stops.
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Solar Wind Interaction and Atmospheric Escape

2017
International ...
Brain, David A., Barabash, Sergey, Bougher, Stephen W., Durut, Firat, Jakosky, Bruce M., Modolo, Ronan   +5 more
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Thermal atmospheric escape of close-in exoplanets

Proceedings of the International Astronomical Union, 2020
AbstractIn this work we applied the previously developed self-consistent 1D model of hydrogen-helium atmosphere with suprathermal electrons to close-in hot neptune GJ 436 b. The obtained height profile of density shows the two-scale structure of the planetary atmosphere. The mass-loss rate is found to be about .
Eugenia S. Kalinicheva, Valery I. Shematovich   +1 more
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Escape of Planetary Atmospheres

2012
The extreme radiation and plasma environments during the period of the young active Sun/Stars have important implications for the evolution of planetary atmospheres and may be responsible that planets with a low gravity like early Mars most likely could never build up a dense atmosphere during the first few 100 Myr after their origin. On the other hand
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Titan's hydrodynamically escaping atmosphere

Icarus, 2008
Abstract The upper atmosphere of Titan is currently losing mass at a rate ∼ ( 4 – 5 ) × 10 28 amu s −1 , by hydrodynamic escape as a high density, slow outward expansion driven principally by solar UV heating by CH4 absorption. The hydrodynamic mass loss is essentially CH4 and H2 escape.
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Escape and Stand of the Pluto Atmosphere

Communications in Theoretical Physics, 2002
Molar mass mu(min) of the lightest gas, Which will exist "forever" in the atmosphere at the planet surface, can be evaluated by Jeans rule. The mu(min) of Pluto is 17.3 g . mol(-1). It is evident that both N-2 and CO can be major atmospheric composition at the Pluto surface, and will exist "forever".
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An attractive problem on atmospheric escape

Journal of Chemical Education, 1980
A question on escape velocity is representative of the wealth of material that can be exploited from applying the gas laws to atmospheric and meteorological phenomenon.
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Photon escape probabilities in expanding atmospheres

Journal of Astrophysics and Astronomy, 1981
A comparison of mean number of scatterings and escape probabilities has been made in isotropic scattering and dipole scattering by using the angle-averaged partial frequency redistribution functionR I. We have solved the equations of radiative transfer and statistical equilibrium simultaneously in a spherically symmetric expanding ...
A. Peraiah, K. E. Rangarajan, D. Mohan Rao   +2 more
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The escape of helium from the Earth's atmosphere

Reviews of Geophysics, 1963
The rate of influx of helium 4 from the earth's crust into the atmosphere is about 2 × 106 atoms cm−2 sec−1. The average rate of thermal escape averaged over the last solar cycle is 6 × 104 atoms cm−2 sec−1. The present abundance of helium in the atmosphere would accumulate in about two million years. Either some nonthermal mechanism permits at present
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