Jeans escape
التعريفات والمعاني
== English ==
=== Etymology ===
Named after English physicist Sir James Jeans (1877–1946), who is credited with calculating the rate of such atmospheric escape.
=== Noun ===
Jeans escape (countable and uncountable, plural Jeans escapes)
(planetology, astrophysics) A type of atmospheric escape in which a light gas atom or molecule (typically a helium atom or hydrogen molecule) gains sufficient momentum through collision with other molecules to escape the atmosphere (and gravitational pull) of a planet.
2014, Eugene F. Milone, William J. F. Wilson, Solar System Astrophysics, Springer, 2nd Edition, page 413,
As will be seem in Sects. 11.7.2.3 and 11.7.3.2, Jeans escape of
H
{\displaystyle {\ce {H}}}
atoms from Venus is negligible compared to other, nonthermal mechanisms, whereas Jeans escape dominates the loss of
H
{\displaystyle {\ce {H}}}
from Mars. On both planets, Jeans escape of
O
{\displaystyle {\ce {O}}}
,
O
2
{\displaystyle {\ce {O2}}}
and
CO
2
{\displaystyle {\ce {CO2}}}
is negligible.
2017, Kevin Heng, Exoplanetary Atmospheres, Princeton University Press, page 213,
The simplest model of Jeans escape [112], a mechanism named after the Englishman James H. Jeans, assumes that the constituent particles of the atmosphere may be described by a Maxwell-Boltzmann distribution,
f
M
=
(
a
π
)
3
/
2
n
e
−
a
v
2
{\displaystyle f_{M}=\left({\frac {a}{\pi }}\right)^{3/2}ne^{-av^{2}}}
, (13.6)
where
a
≡
m
/
2
k
B
T
{\displaystyle a\equiv m/2k_{B}T}
,
n
{\displaystyle n}
is the number density of particles and
v
{\displaystyle v}
is the magnitude of the velocity.
2021, Mark H. Thiemens, Mang Lin, 2: Discoveries of Mass Independent Isotope Effects in the Solar System, Ilya N. Bindeman, Andreas Pack (editors), Reviews in Mineralogy and Geochemistry, Volume 86: Triple Oxygen Isotope Geochemistry, Mineralogical Society of America, page 70,
The hydrogen is lost from the system by diffusion and Jeans escapes.
==== Translations ====