DOI: 10.1073/pnas.2006177117
论文题名: Exoplanet secondary atmosphere loss and revival
作者: Kite E.S. ; Barnett M.N.
刊名: Proceedings of the National Academy of Sciences of the United States of America
ISSN: 0027-8424
出版年: 2020
卷: 117, 期: 31 起始页码: 18264
结束页码: 18271
语种: 英语
英文关键词: Atmospheric evolution
; Exoplanets
; Planetary science
Scopus关键词: Article
; astronomy
; atmosphere
; crystallization
; mathematical model
; molecular weight
; priority journal
; volcano
英文摘要: The next step on the path toward another Earth is to find atmospheres similar to those of Earth and Venus-high-molecularweight (secondary) atmospheres-on rocky exoplanets. Many rocky exoplanets are born with thick (>10 kbar) H2-dominated atmospheres but subsequently lose their H2; this process has no known Solar System analog. We study the consequences of early loss of a thick H2 atmosphere for subsequent occurrence of a high-molecularweight atmosphere using a simple model of atmosphere evolution (including atmosphere loss to space, magma ocean crystallization, and volcanic outgassing). We also calculate atmosphere survival for rocky worlds that start with no H2. Our results imply that most rocky exoplanets orbiting closer to their star than the habitable zone that were formed with thick H2-dominated atmospheres lack high-molecularweight atmospheres today. During early magma ocean crystallization, high-molecular-weight species usually do not form long-lived high-molecular-weight atmospheres; instead, they are lost to space alongside H2. This early volatile depletion also makes it more difficult for later volcanic outgassing to revive the atmosphere. However, atmospheres should persist on worlds that start with abundant volatiles (for example, water worlds). Our results imply that in order to find high-molecular-weight atmospheres on warm exoplanets orbiting M-stars, we should target worlds that formed H2-poor, that have anomalously large radii, or that orbit less active stars. © 2020 National Academy of Sciences. All rights reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/164101
Appears in Collections: 气候变化与战略
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作者单位: Kite, E.S., Department of Geophysical Sciences, University of Chicago, Chicago, IL 60637, United States; Barnett, M.N., Department of Geophysical Sciences, University of Chicago, Chicago, IL 60637, United States
Recommended Citation:
Kite E.S.,Barnett M.N.. Exoplanet secondary atmosphere loss and revival[J]. Proceedings of the National Academy of Sciences of the United States of America,2020-01-01,117(31)