TY - JOUR
T1 - Increased hydrogen escape from Mars atmosphere during periods of high obliquity
AU - Gilli, Gabriella
AU - González-Galindo, Francisco
AU - Chaufray, Jean Yves
AU - Millour, Ehouarn
AU - Forget, François
AU - Montmessin, Franck
AU - Lefèvre, Franck
AU - Naar, Joseph
AU - Luo, Yangcheng
AU - Vals, Margaux
AU - Rossi, Loïc
AU - López-Valverde, Miguel Ángel
AU - Brines, Adrián
N1 - Publisher Copyright:
© The Author(s), under exclusive licence to Springer Nature Limited 2025.
PY - 2025/7/1
Y1 - 2025/7/1
N2 - It is still unknown how much water has escaped from Mars during its history. Hydrogen escape from Mars’s atmosphere probably played a major role in drying the planet, but present-day H loss rates (~3 × 1026 atoms per second on average) cannot explain the geological evidence for the large volumes of liquid water on ancient Mars. Here we used the three-dimensional Mars-Planetary Climate Model to show that H loss rates could have increased by more than one order of magnitude (6 × 1027 atoms per second) during higher spin axis obliquity periods, notably in the last few million years when Mars’s obliquity was about 35° on average. The resulting accumulated H escape over Mars’s history translates into an ~80 m global equivalent layer, which is close to the lower limit of geological estimates, assessing the major role of atmospheric escape in drying Mars.
AB - It is still unknown how much water has escaped from Mars during its history. Hydrogen escape from Mars’s atmosphere probably played a major role in drying the planet, but present-day H loss rates (~3 × 1026 atoms per second on average) cannot explain the geological evidence for the large volumes of liquid water on ancient Mars. Here we used the three-dimensional Mars-Planetary Climate Model to show that H loss rates could have increased by more than one order of magnitude (6 × 1027 atoms per second) during higher spin axis obliquity periods, notably in the last few million years when Mars’s obliquity was about 35° on average. The resulting accumulated H escape over Mars’s history translates into an ~80 m global equivalent layer, which is close to the lower limit of geological estimates, assessing the major role of atmospheric escape in drying Mars.
UR - https://www.scopus.com/pages/publications/105005587719
U2 - 10.1038/s41550-025-02561-3
DO - 10.1038/s41550-025-02561-3
M3 - Article
AN - SCOPUS:105005587719
SN - 2397-3366
VL - 9
SP - 960
EP - 968
JO - Nature Astronomy
JF - Nature Astronomy
IS - 7
ER -
