In the origin of the satellites of Mars are still controversial. [28] Phobos and Deimos, both have much in common with carbon C-type asteroids with spectra, albedos and densities very similar to C or D-type asteroids. [12] Based on this similarity, one hypothesis is that the two Moons, may have been captured in Mars orbit from the main belt asteroids. [29] [30] Both Moons is circular orbit that lies almost exactly in Mars' equatorial plane, and hence the seizure origin requires a mechanism for circularizing initially highly eccentric orbits, and the adjustment of its inclination to the equatorial plane, most likely through a combination of atmospheric braking and tidal forces, [31], although it is not clear that there is enough time for this to occur for Deimos. [28] Capture also requires energy dissipation. The current atmosphere of Mars is too thin to capture the size of the object Phobos atmospheric braking. [28] Geoffrey Landis noted that the seizure could occur if the original body is a binary asteroid, which are separated due to tidal forces. [30] The main alternative hypothesis is that the Moons accreted in this situation. Another hypothesis is that Mars was once surrounded by many of Phobos and Deimos size of possibly ejected into orbit around a collision with a large planetesimal