Submitted by Anonymous on Wed, 10/14/2009 - 05:48.
L4 and L5 aren't where Phobos' gravitational effect approaches zero. L4 and L5 are the Trojan points; they are always in the same orbit (as Phobos, in this case), but 60 degrees ahead or behind.
Given the relatively VERY small mass of Phobos and Deimos, I doubt there's any measurable effect on orbit stability (read: an orbit almost anywhere will be stable enough). If anything, I'd expect Deimos' to be more stable, as it's further out and Phobos is beneath it, rather than above it.
l4 and l5
L4 and L5 aren't where Phobos' gravitational effect approaches zero. L4 and L5 are the Trojan points; they are always in the same orbit (as Phobos, in this case), but 60 degrees ahead or behind.
Given the relatively VERY small mass of Phobos and Deimos, I doubt there's any measurable effect on orbit stability (read: an orbit almost anywhere will be stable enough). If anything, I'd expect Deimos' to be more stable, as it's further out and Phobos is beneath it, rather than above it.