|
|
SPRG Seminars - Archive
January 24, 2006:
Electron reflectometry as a probe of the Martian crust and atmosphere
Rob Lillis, UCB/Space Sciences Laboratory
The magnetometer and electron reflectometer on board Mars Global surveyor measures the local electron population's distribution in both energy and pitch angle. The solar wind electrons traveling towards the planet along open magnetic field lines are magnetically reflected by magnetic sources in the Martian crust and are absorbed and scattered by the neutral atmosphere. By studying the pitch angle dependence of the reflected and scattered electrons, we may determine properties of the Martian crustal magnetic field and the density of the Martian neutral atmosphere between 150 km and 190 km altitude. We present results from six years of mapping orbit data and attempt to constrain 1) the magmatic history of Martian
volcanoes, 2) when the the early Martian dynamo ceased operating and 3) the seasonal and latitude dependence of neutral densities in the upper Martian thermosphere.