April 30, 2010, 12:00 pm - 1:00 pm

April 30, 2010, 12:00 pm - 1:00 pm

The Ins and Outs of Martian Mini-Magnetospheres

Dave Brain (UC Berkeley, SSL)

Measurements of magnetic fields and charged particles near Mars made over the past four decades have taught us about its plasma environment, upper atmosphere, near-surface radiation environment, subsurface, and deep interior. The upper atmosphere and plasma environment of Mars are of interest because they are the sites of energy exchange between the planet and its surroundings, dominated by the Sun and solar wind. For this reason they may have played a critical role in martian climate evolution. A number of recent spacecraft observations demonstrate that the exchange of particles and energy between the solar wind and atmosphere is particularly dynamic at Mars because strong localized crustal magnetic fields form mini-magnetospheres that rotate with the planet, influencing the motion of charged particles. I will discuss two observed influences of crustal fields on particle motion near Mars and their implications: episodic escape of atmospheric particles via detached crustal fields and localized energy deposition characterized by ultraviolet aurora on the Martian night side.