Abstract
With both the Mars Atmosphere and Volatile Evolution (MAVEN) mission and
the Interior Exploration using Seismic Investigations, Geodesy and Heat
Transport (InSight) mission concurrently operating at Mars, we are able
to make two point comparisons of the vector magnetic field at Mars for
the first time. During MAVEN overflights of the InSight landing site, we
compared deviations in the ionospheric magnetic field to variations in
the surface level magnetic field. We find significant orbit to orbit
variability in the magnitude and direction of the ionospheric magnetic
field as well as significant day to day variability of the surface level
magnetic field. We attribute this variability to time varying
ionospheric currents. However, when analyzing the ensemble of 16
individual MAVEN overflights of the InSight landing location, we see no
clear correlation between the magnitudes or directions of the
ionospheric magnetic field and the surface magnetic field as might be
expected. If the presumed ionospheric currents have a small scale size,
then the ionospheric magnetic field will display increased variability
as MAVEN flies through the current structure. Whereas the present
analysis is restricted to mostly nightside MAVEN overflights where
current are expected to be weak, future analyses should incorporate
dayside overflights where current are expected to be stronger and
current signatures more clear.