25 Sep 2010

At September 22nd ... (see also ) scientists claim to have found firm evidence that the biggest moon of Mars, Phobus, is made from rock blasted off the surface of Mars in a catastrophic event - something like worlds in collision! The evidence comes from ESAs Mars Express spacecraft and appears to discount the old theory the moons of Mars are captured asteroids. However, somewhat strangely, Phobos is an acretion - possibly formed from ejected material into a sort of lump with holes and channels and hollow spaces. A Russian robotic mission to Phobos next year is due to investigate the composition more thoroughly.