Martian moons Phobos and Deimos carved out by violent impact
April 18 (UPI) -- The Martian moons Phobos and Deimos were formed after a large object struck the Red Planet a few billion years ago, according to a new model developed by scientists at the Southwest Research Institute.Scientists have considered a number of origin scenarios for Phobos and Deimos, including the possibility that the satellites are asteroids captured by Mars' gravity.The most promising formation theory is one involving an impact and an equatorial disk of debris. The two small moons formed from the disk of rocky fragments. But until now, attempts to model such a scenario have failed to convince."Ours is the first self-consistent model to identify the type of impact needed to lead to the formation of Mars' two small moons," Robin Canup, an associate vice president in the SwRI S...