Comparative Na and K Mercury and Moon Exospheres

François Leblanc (1) , C. Schmidt (2) , Valeria Mangano (3) , A. Mura (3) , G. Cremonese (4) , J. M. Raines (5) , J. M. Jasinski (6) , M. Sarantos (7) , A. Milillo (3) , R. M. Killen (7) , S. Massetti (3) , T. Cassidy (8) , R. J. Vervack (9) , S. Kameda (10) , M. T. Capria (3) , M. Horanyi (8) , D. Janches (7) , A. Berezhnoy (11, 12) , A. Christou (13) , T. Hirai (14) , P. Lierle (14) , J. Morgenthaler (15)

1 HELIOS - LATMOS
2 CSP - Center for Space Physics [Boston]
3 IAPS - Istituto di Astrofisica e Planetologia Spaziali - INAF
4 OAPD - INAF - Osservatorio Astronomico di Padova
5 CLaSP - Department of Climate and Space Sciences and Engineering
6 JPL - Jet Propulsion Laboratory
7 GSFC - NASA Goddard Space Flight Center
8 LASP - Laboratory for Atmospheric and Space Physics [Boulder]
9 APL - Johns Hopkins University Applied Physics Laboratory [Laurel, MD]
10 Rikkyo University [Tokyo]
11 Sternberg Astronomical Institute [Moscow]
12 IoP - Institute of Physics [Kazan]
13 Armagh Observatory [Armagh]
14 PERC - Planetary Exploration Research Center [Chiba]
15 PSI - Planetary Science Institute [Tucson]

Sodium and, in a lesser way, potassium atomic components of surface-bounded exospheres are among the brightest elements that can be observed from the Earth in our Solar System. Both species have been intensively observed around Mercury, the Moon and the Galilean Moons. During the last decade, new observations have been obtained thanks to space missions carrying remote and in situ instrumentation that provide a completely original view of these species in the exospheres of Mercury and the Moon. They challenged our understanding and modelling of these exospheres and opened new directions of research by suggesting the need to better take into account the relationship between the surface-exosphere and the magnetosphere. In this paper, we first review the large set of observations of Mercury and the Moon Sodium and Potassium exospheres. In the second part, we list what it tells us on the sources and sinks of these exospheres focusing in particular on the role of their magnetospheres of these objects and then discuss, in a third section, how these observations help us to understand and identify the key drivers of these exospheres.

Mots clés: Surface-bounded exosphere; Mercury and the Moon; Sodium and potassium atomic species; Surface-exosphere-magnetosphere interaction; Ground based observations

Domaines: Planète et Univers [physics]

François Leblanc, C. Schmidt, Valeria Mangano, A. Mura, G. Cremonese, et al.. Comparative Na and K Mercury and Moon Exospheres. Space Science Reviews, 2022, 218 (1), pp.art. 2. ⟨10.1007/s11214-022-00871-w⟩. ⟨insu-03541032⟩