Loss of the Martian atmosphere to space: Present-day loss rates determined from MAVEN observations and integrated loss through time

Authors

B. M. Jakosky, University of Colorado Boulder
D. Brain, University of Colorado Boulder
M. Chaffin, University of Colorado Boulder
S. Curry, Space Sciences Laboratory at UC Berkeley
J. Deighan, University of Colorado Boulder
J. Grebowsky, NASA Goddard Space Flight Center
J. Halekas, University of Iowa
F. Leblanc, Laboratoire Atmosphères, Milieux, Observations Spatiales
R. Lillis, Space Sciences Laboratory at UC Berkeley
J. G. Luhmann, Space Sciences Laboratory at UC Berkeley
L. Andersson, University of Colorado Boulder
N. Andre, Université Fédérale Toulouse Midi-Pyrénées
D. Andrews, Instiutet för rymdfysik
D. Baird, NASA Johnson Space Center
D. Baker, University of Colorado Boulder
J. Bell, National Institute of Aerospace
M. Benna, NASA Goddard Space Flight Center
D. Bhattacharyya, Boston University
S. Bougher, University of Colorado Boulder
C. Bowers, University of Colorado Boulder
P. Chamberlin, University of Colorado Boulder
J. Y. Chaufray, Laboratoire Atmosphères, Milieux, Observations Spatiales
J. Clarke, Boston University
G. Collinson, NASA Goddard Space Flight Center
M. Combi, University of Michigan, Ann Arbor
J. Connerney, NASA Goddard Space Flight Center
K. Connour, University of Colorado Boulder
J. Correira, CPI, Inc.
K. Crabb, University of Colorado Boulder
F. Crary, University of Colorado Boulder
T. Cravens, Kansas University
M. Crismani, University of Colorado Boulder
G. Delory, Space Sciences Laboratory at UC Berkeley

Document Type

Article

Publication Date

2018

Department/School

Physics and Astronomy

Publication Title

Icarus

Abstract

Observations of the Mars upper atmosphere made from the Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft have been used to determine the loss rates of gas from the upper atmosphere to space for a complete Mars year (16 Nov 2014 – 3 Oct 2016). Loss rates for H and O are sufficient to remove ∼2–3 kg/s to space. By itself, this loss would be significant over the history of the planet. In addition, loss rates would have been greater early in history due to the enhanced solar EUV and more-active Sun. Integrated loss, based on current processes whose escape rates in the past are adjusted according to expected solar evolution, would have been as much as 0.8 bar CO2 or 23 m global equivalent layer of H2O; these losses are likely to be lower limits due to the nature of the extrapolation of loss rates to the earliest times. Combined with the lack of surface or subsurface reservoirs for CO2 that could hold remnants of an early, thick atmosphere, these results suggest that loss of gas to space has been the dominant process responsible for changing the climate of Mars from an early, warmer environment to the cold, dry one that we see today.

Link to Published Version

10.1016/j.icarus.2018.05.030

Recommended Citation

Jakosky, B. M., Brain, D., Chaffin, M., Curry, S., Deighan, J., Grebowsky, J., Halekas, J., Leblanc, F., Lillis, R., Luhmann, J. G., Andersson, L., Andre, N., Andrews, D., Baird, D., Baker, D., Bell, J., Benna, M., Bhattacharyya, D., Bougher, S., … Zurek, R. (2018). Loss of the Martian atmosphere to space: Present-day loss rates determined from MAVEN observations and integrated loss through time. Icarus, 315, 146–157. https://doi.org/10.1016/j.icarus.2018.05.030