Moons of Mars formed a large moon. Gravitational interactions between this moon and the outer ring formed Phobos and Deimos. Later, the large moon crashed into Mars, but the two small moons remained in orbit. This theory agrees with the fine-grained surface of the moons and their high porosity. The outer disk would create fine-grained material. While many Martian probes provided images and other data about Phobos and Deimos, only few were dedicated to these satellites and intended to perform a flyby or landing on the surface. Two probes under the Soviet Phobos program were successfully launched in 1988, but neither conducted the
Mars One developing the technology needed, it is unclear what the astronauts would be training for. Mars One has stated that the teams selected will be undergoing a battery of training, ranging from psycho-social skills to engineering and scientific observation. Mars One funding comes from astronaut application fees, donations, undisclosed private investment, intellectual property (IP) rights, and mostly, the potential sale of future broadcasting rights. Over three quarters of the funds would reportedly go to concept design studies. Mars One states that "income from donations and merchandise have not been used to pay salaries". To date, no financial records have been released