Funding for this research was provided by:
National Aeronautics and Space Administration (12-ACMAP12-0010)
Article History
Received: 10 April 2018
Accepted: 6 September 2018
First Online: 20 September 2018
Competing interests
: The authors declare that they have no competing interests.
: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.