Considering the relative velocities of Mars and the comet, that material will slam into the Red Planet's atmosphere at more than 57 km / sec — a process that will heat the air and cause it to expand, fluffing upward to increase atmospheric drag on craft orbiting the planet (thereby slowing down the orbiters slightly but not substantially threatening them). (sciencemag.org)
In such paths, a cascade of collisions would have blasted any orbs present there into ever smaller bits, which in turn would have been slowed by the interplanetary equivalent of atmospheric drag and eventually plunged into the sun, the researchers report online this week in the Proceedings of the National Academy of Sciences. (sciencemag.org)
The spacecraft will circle Mars once every 118 minutes in an orbit inclined at 93 degrees to the equator and 378 kilometres above the surface — low enough to get detailed pictures but high enough to avoid atmospheric drag. (newscientist.com)