Moons of Mars binary asteroid that separated under tidal forces. Phobos could be a second-generation Solar System object that coalesced in orbit after Mars formed, rather than forming concurrently out of the same birth cloud as Mars. Another hypothesis is that Mars was once surrounded by many Phobos- and Deimos-sized bodies, perhaps ejected into orbit around it by a collision with a large planetesimal. The high porosity of the interior of Phobos (based on the density of 1.88 g/cm, voids are estimated to comprise 25 to 35 percent of Phobos' volume) is inconsistent with an asteroidal origin. Observations of Phobos in the thermal
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