Terrestrial planet atmospheres in the aftermath of giant impacts - Roxan...
Δημοσιεύτηκε στις 9 Ιουλ 2014
Abstract: The final assembly of
terrestrial planets is now universally thought to have occurred through a
series of giant impacts, such as Earth's own Moon-forming impact. In
the aftermath of one of these collisions the surviving planet is hot,
and can remain hot for millions of years. The presence of a dense
post-impact atmosphere will affect both the cooling of the planet and
our ability to detect it. Dr. Lupu will present modeling results
regarding the structure, chemistry, and spectral signatures of the
atmospheres consisting of vaporized rock material. The atmospheric gas
is in equilibrium with the surface magma ocean, with compositions
reflecting either the bulk silicate Earth (which includes the crust,
mantle, atmosphere and oceans) or the Earth's continental crust as a
separate case. Dr. Lupu and her colleagues found that these atmospheres
are dominated by H2O and CO2, and present characteristic spectral
features from HF, HCl, and SO2. They estimate that cooling timescales
for post-giant impact Earths range between about 10^5 and 10^6 years,
where the slower cooling is associated with the planet going through a
runaway greenhouse stage.
terrestrial planets is now universally thought to have occurred through a
series of giant impacts, such as Earth's own Moon-forming impact. In
the aftermath of one of these collisions the surviving planet is hot,
and can remain hot for millions of years. The presence of a dense
post-impact atmosphere will affect both the cooling of the planet and
our ability to detect it. Dr. Lupu will present modeling results
regarding the structure, chemistry, and spectral signatures of the
atmospheres consisting of vaporized rock material. The atmospheric gas
is in equilibrium with the surface magma ocean, with compositions
reflecting either the bulk silicate Earth (which includes the crust,
mantle, atmosphere and oceans) or the Earth's continental crust as a
separate case. Dr. Lupu and her colleagues found that these atmospheres
are dominated by H2O and CO2, and present characteristic spectral
features from HF, HCl, and SO2. They estimate that cooling timescales
for post-giant impact Earths range between about 10^5 and 10^6 years,
where the slower cooling is associated with the planet going through a
runaway greenhouse stage.
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