As I understand it, Mars has 2 asteroids in orbit. One slowly moving away from Mars, the other on an orbital collision course. Could the collision possibly be violent enough to liquify the planets mantle? If so, would Mars re-establish a magnetic field? Is there sufficient ice in the polar caps to thaw and create an atmosphere? Would a newly evolved Mars with protection for it's atmoshere in the form of a magnetic field be a possibility as a result of this impact?