In APOD, there's a good (and enlargeable) picture of Phobos!
Discovered in 1877, when Mars was as its closest (until august 2003 when it will come even closer), and guessed by Swift long before! (Perhaps because the Earth had one moon and Jupiter four galilean moons, therefore Mars, between the two, would "logically" have two moons, or just a fortuitous reasoning;).
Last night, I went to an open door day at an astronomy club (friends) and students showed a great planets software . At one point, showng the Hellas basin versus the Tharsis buldge, they talked about the known impact theory that formed both of them (through a shockwave) but also the same impact might have formed Phobos and Deimos, to which I replied : Hellas isn't on the equator....How can they have formed 2 moons in an equatorial orbit? (Unless they moved towards this orbit, with time).

Raoul