Discovery of diffuse aurora on Mars

Nicholas M. Schneider (1) , Justin I. Deighan (1) , Sonal K. Jain (1) , Arnaud Stiepen (1) , A. Ian F. Stewart (1) , Davin Larson (2) , David L. Mitchell (2) , Christian Mazelle (3) , Christina O. Lee (2) , Robert J. Lillis (2) , J. Scott Evans (4) , David Brain (1) , Michael H. Stevens (5) , William E. Mcclintock (1) , Michael S. Chaffin (1) , Matteo Crismani (1) , Greg M. Holsclaw (1) , Franck Lefèvre (6) , Daniel Y. Lo (7) , John T. Clarke (8) , Franck Montmessin (6) , Bruce M. Jakosky (1)

1 LASP - Laboratory for Atmospheric and Space Physics [Boulder]
2 SSL - Space Sciences Laboratory [Berkeley]
3 IRAP - Institut de recherche en astrophysique et planétologie
4 Computational Physics, Inc.
5 NRL - Naval Research Laboratory
6 PLANETO - LATMOS
7 LPL - Lunar and Planetary Laboratory [Tucson]
8 CSP - Center for Space Physics [Boston]

Planetary auroras reveal the complex interplay between an atmosphere and the surrounding plasma environment. We report the discovery of low-altitude, diffuse auroras spanning much of Mars’ northern hemisphere, coincident with a solar energetic particle outburst. The Imaging Ultraviolet Spectrograph, a remote sensing instrument on the Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft, detected auroral emission in virtually all nightside observations for ~5 days, spanning nearly all geographic longitudes. Emission extended down to ~60 kilometer (km) altitude (1 microbar), deeper than confirmed at any other planet. Solar energetic particles were observed up to 200 kilo­–electron volts; these particles are capable of penetrating down to the 60 km altitude. Given minimal magnetic fields over most of the planet, Mars is likely to exhibit auroras more globally than Earth.

Domaines: Océan, Atmosphère; Planétologie et astrophysique de la terre [astro-ph.EP]

Nicholas M. Schneider, Justin I. Deighan, Sonal K. Jain, Arnaud Stiepen, A. Ian F. Stewart, et al.. Discovery of diffuse aurora on Mars. Science, 2015, 350 (6261), pp.aad0313. ⟨10.1126/science.aad0313⟩. ⟨insu-01227468⟩