Journal
ASTROPHYSICAL JOURNAL
Volume 824, Issue 2, Pages -Publisher
IOP PUBLISHING LTD
DOI: 10.3847/0004-637X/824/2/103
Keywords
planets and satellites: atmospheres; planets and satellites: composition; planets and satellites: formation; planets and satellites: general; planets and satellites: terrestrial planets
Categories
Funding
- NSF Astronomy Program [AST-1412175]
- NASA EPSCOR Program [NNX13AE52A]
- NASA EPSCOR Program
- NASA Glenn Research Center
- McDonnell Center Roger B. Chaffee Fellowship
- European Research Council [291332-CODITA]
- Simons Foundation
- Direct For Mathematical & Physical Scien
- Division Of Astronomical Sciences [1517541] Funding Source: National Science Foundation
- Direct For Mathematical & Physical Scien
- Division Of Astronomical Sciences [1412175] Funding Source: National Science Foundation
Ask authors/readers for more resources
Extensive experimental studies show that all major rock-forming elements (e.g., Si, Mg, Fe, Ca, Al, Na, K) dissolve in steam to a greater or lesser extent. We use these results to compute chemical equilibrium abundances of rocky-element-bearing gases in steam atmospheres equilibrated with silicate magma oceans. Rocky elements partition into steam atmospheres as volatile hydroxide gases (e.g., Si(OH)(4), Mg(OH)(2), Fe(OH)(2), Ni(OH)(2), Al(OH)(3), Ca(OH)(2), NaOH, KOH) and via reaction with HF and HCl as volatile halide gases (e.g., NaCl, KCl, CaFOH, CaClOH, FAl(OH)(2)) in much larger amounts than expected from their vapor pressures over volatile-free solid or molten rock at high temperatures expected for steam atmospheres on the early Earth and hot rocky exoplanets. We quantitatively compute the extent of fractional vaporization by defining gas/magma distribution coefficients and show that Earth's subsolar Si/Mg ratio may be due to loss of a primordial steam atmosphere. We conclude that hot rocky exoplanets that are undergoing or have undergone escape of steam-bearing atmospheres may experience fractional vaporization and loss of Si, Mg, Fe, Ni, Al, Ca, Na, and K. This loss can modify their bulk composition, density, heat balance, and interior structure.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available