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

Bruce M. Jakosky (1) , David A. Brain (1) , Michael S. Chaffin (1) , Shannon M. Curry (2) , Justin Deighan (1) , Joseph M. Grebowsky (3) , Jasper S. Halekas (4) , François Leblanc (5) , Robert J. Lillis (2) , Janet G. Luhmann (2) , Laila Andersson (1) , Nicolas André (6) , David J. Andrews (7) , Darren T. Baird (8) , Daniel N. Baker (1) , Jared M. Bell (9) , Mehdi Benna (3) , Dolon Bhattacharyya (10) , Stephen W. Bougher (11) , Charlie Bowers (1) , Phillip Chamberlin (1) , Jean-Yves Chaufray (5) , John Clarke (10) , Glyn Collinson (3) , Michael Combi (12) , Jack Connerney (3) , Kyle Connour (1) , J. Correira (13) , Kyle Crabb (1) , Frank Crary (1) , Thomas Cravens (14) , Matteo Crismani (1) , Greg Delory (2) , Ryan Dewey (1) , Gina Dibraccio (3) , Chuanfei Dong (15) , Yaxue Dong (1) , Patrick Dunn (2) , Hilary Egan (16) , Meredith K. Elrod (3) , Scott England (2) , Frank Eparvier (1) , Robert Ergun (1) , Anders I. Eriksson (7) , Teresa Esman (17) , Jared R. Espley (3) , S. Evans (13) , Kathryn Fallows (10) , Xiaohua Fang (1) , Matthew Fillingim (2) , C. Flynn (18) , A. Fogle (2) , Christopher M. Fowler (1) , Jane L. Fox (19) , Masaki Fujimoto (20) , Philippe Garnier (6) , Zachary R. Girazian (3) , Hannes Groeller (17) , Jacob R. Gruesbeck (3) , O. Hamil (14) , K. G. Hanley (1) , Takuya Hara (2) , Yuki Harada (21) , Jacob Hermann (1) , Mika Holmberg (6) , Greg M. Holsclaw (1) , S. Houston (22) , S. Inui (23) , Sonal K. Jain (1) , Rebecca Jolitz (1) , Anna Kotova (6) , Takeshi Kuroda (24) , Davin Larson (2) , Yuni Lee (3) , C. Lee (2) , Franck Lefèvre (25) , Christy Lentz (1) , D. Lo (17) , Rafael Lugo (26) , Yingjuan Ma (27) , Paul R. Mahaffy (3) , Melissa L. Marquette (2) , Y. Matsumoto (23) , Majd Mayyasi (10) , Christian Mazelle (6) , William Mcclintock (1) , Jim Mcfadden (2) , A. Medvedev (28) , Michael Mendillo (10) , K. Meziane (29) , Zachariah Milby (1) , D. Mitchell (2) , Ronan Modolo (5) , Franck Montmessin (25) , Andrew Nagy (12) , H. Nakagawa (30) , Clara Narvaez (10) , Kirk J. Olsen (11) , D. Pawlowski (31) , William Peterson (1) , Ali Rahmati (2) , Kali J. Roeten (32) , Norberto Romanelli (5) , Suranga Ruhunusiri (21) , Christopher T. Russell (33) , Shotaro Sakai (34) , Nicholas M. Schneider (1) , K. Seki (23) , R. Sharrar (32) , S. Shaver (1) , David E. Siskind (35) , Marek Slipski (1) , Yasir I. J. Soobiah (3) , Morgane Steckiewicz (6) , Michael H. Stevens (35) , Ian Stewart (1) , Arnaud Stiepen (36) , S. Stone (17) , Valeriy Tenishev (11) , Naoki Terada (37) , Kaori Terada (37) , Edward Thiemann (1) , R. Tolson (9) , G. Toth (11) , Jeffrey Trovato (18) , M. Vogt (18) , Tristan Weber (1) , P. Withers (18) , Shaosui Xu (2) , Roger Yelle (38) , Erdal Yiğit (39) , Richard Zurek (40)

1 LASP - Laboratory for Atmospheric and Space Physics [Boulder]
2 SSL - Space Sciences Laboratory [Berkeley]
3 GSFC - NASA Goddard Space Flight Center
4 Department of Physics and Astronomy [Iowa City]
5 HELIOS - LATMOS
6 IRAP - Institut de recherche en astrophysique et planétologie
7 IRF - Swedish Institute of Space Physics [Uppsala]
8 JSC - NASA Johnson Space Center
9 NIA - National Institute of Aerospace [Hampton]
10 CSP - Center for Space Physics [Boston]
11 CLaSP - Department of Climate and Space Sciences and Engineering
12 AOSS - Department of Atmospheric, Oceanic, and Space Sciences [Ann Arbor]
13 CPI - Communications and Power Industries
14 Department of Physics and Astronomy [Lawrence Kansas]
15 Princeton University
16 University of Colorado [Boulder]
17 University of Arizona
18 BU - Boston University [Boston]
19 Wright State University
20 ISAS - Institute of Space and Astronautical Science
21 Department of Physics and Astronomy [Ames, Iowa]
22 University of Kansas [Kansas City]
23 UTokyo - The University of Tokyo
24 NICT - National Institute of Information and Communications Technology [Tokyo, Japan]
25 PLANETO - LATMOS
26 Analytical Mechanics Associates, Inc.
27 UCLA - University of California [Los Angeles]
28 MPS - Max-Planck-Institut für Sonnensystemforschung
29 UNB - University of New Brunswick
30 Tohoku University [Sendai]
31 Eastern Michigan University
32 University of Michigan [Ann Arbor]
33 IGPP - Institute of Geophysics and Planetary Physics [Los Angeles]
34 Department of Earth and Planetary Science [Tokyo]
35 NRL - Naval Research Laboratory
36 LPAP - Laboratoire de Physique Atmosphérique et Planétaire
37 Graduate School of Information Sciences [Sendai]
38 LPL - Lunar and Planetary Laboratory [Tucson]
39 Department of Physics and Astronomy [Fairfax]
40 JPL - Jet Propulsion Laboratory

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.

Keywords: Mars climate; Mars; Magnetospheres; Atmosphere; Mars atmosphere; Solar wind

Domains: Astrophysics [astro-ph]

Bruce M. Jakosky, David A. Brain, Michael S. Chaffin, Shannon M. Curry, Justin Deighan, et al.. Loss of the Martian atmosphere to space: Present-day loss rates determined from MAVEN observations and integrated loss through time. Icarus, 2018, 315, pp.146-157. ⟨10.1016/j.icarus.2018.05.030⟩. ⟨insu-01807507⟩