Journal article
Discovery of a proton aurora at Mars
Nature Astronomy, Vol.2(10), pp.802-807
01/01/2018
DOI: 10.1038/s41550-018-0538-5
Abstract
International audience; Proton aurorae are a distinct class of auroral phenomena caused by energetic protons precipitating into a planetary atmosphere. The defining observational signature is atomic hydrogen emissions from the precipitating particles after they obtain an electron from the neutral atmospheric gas, a process known as charge exchange. Until now, proton aurorae have been observed at Earth only. Here, we present evidence of auroral activity driven by precipitating protons at Mars, using observations by the MAVEN spacecraft. We observed transient brightening of upper atmospheric hydrogen Lyman-α emission across the Martian dayside correlated with solar wind activity. The driving mechanism is one not found at Earth and originates from energetic neutral atom production by solar wind protons directly interacting with the extended hydrogen corona surrounding Mars. We characterize this new type of Martian aurora and compare the observed emissions with preliminary modelling guided by simultaneous in situ particle measurements. These observations provide insights into how the solar wind can directly deposit energy into the Martian atmosphere as well as all other planetary objects that are surrounded by a substantial neutral corona exposed to the solar wind.
Details
- Title: Subtitle
- Discovery of a proton aurora at Mars
- Creators
- J Deighan - University of Colorado BoulderS Jain - University of Colorado BoulderM Chaffin - University of Colorado BoulderX Fang - University of Colorado BoulderJ Halekas - University of IowaJ Clarke - Boston UniversityN Schneider - University of Colorado BoulderA StewartJean-Yves Chaufray - LATMOS/IPSL, Guyancourt, FranceJ S Evans - Computational Physics (United States)M Stevens - United States Naval Research LaboratoryM Mayyasi - Boston UniversityA Stiepen - University of LiègeM Crismani - University of Colorado BoulderW Mcclintock - University of Colorado BoulderG Holsclaw - University of Colorado BoulderD Lo - University of ArizonaFranck Montmessin - LATMOS/IPSL, Guyancourt, FranceFranck Lefèvre - LATMOS/IPSL, Guyancourt, FranceB Jakosky - University of Colorado Boulder
- Resource Type
- Journal article
- Publication Details
- Nature Astronomy, Vol.2(10), pp.802-807
- DOI
- 10.1038/s41550-018-0538-5
- ISSN
- 2397-3366
- eISSN
- 2397-3366
- Publisher
- Nature Publishing Group
- Language
- English
- Date published
- 01/01/2018
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9984200036102771
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