A new measurement of D/H on Mars using EXES aboard SOFIA

Thérèse Encrenaz (1) , Curtis N. Dewitt (2) , Matthew J. Richter (2) , Thomas K. Greathouse (3) , Thierry Fouchet (1, 4) , Franck Montmessin (5) , Franck Lefèvre (5) , Bruno Bézard (1) , Sushil K. Atreya (6) , S. Aoki (7)

1 LESIA (UMR_8109) - Laboratoire d'études spatiales et d'instrumentation en astrophysique
2 UC Davis - University of California [Davis]
3 SwRI - Southwest Research Institute [San Antonio]
4 Pôle Planétologie du LESIA
5 PLANETO - LATMOS
6 University of Michigan [Ann Arbor]
7 BIRA-IASB - Belgian Institute for Space Aeronomy / Institut d'Aéronomie Spatiale de Belgique

The distribution of D/H ratio on Mars is crucial for understanding the planet’s water cycle including the exchange with surface reservoirs, and for estimating the amount of liquid water in the past. We have employed EXES (Echelle Cross Echelle Spectrograph) aboard SOFIA (Stratospheric Observatory For Infrared Astronomy) to map D/H on Mars in the thermal infrared, starting with the first measurement in April 2014 (Ls = 113°). Here we present a new measurement obtained in March 2016 (Ls = 127°). The disk-integrated value of D/H is found be 4.0 (+0.7, -0.6) x VSMOW, in agreement with our earlier result (4.4 (+1.0, -0.6) x VSMOW) [3]

Domaines: Astrophysique [astro-ph]

Thérèse Encrenaz, Curtis N. Dewitt, Matthew J. Richter, Thomas K. Greathouse, Thierry Fouchet, et al.. A new measurement of D/H on Mars using EXES aboard SOFIA. European Planetary Science Congress 2017, Sep 2017, Riga, Latvia. pp.EPSC2017-168. ⟨hal-03803290v2⟩