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 2013. Canadian former astronaut Julie Payette said during the opening speech for an International Civil Aviation Organization conference that she does not think Mars One "is sending anybody anywhere". In January 2014, German former astronaut Ulrich Walter strongly criticized the project for ethical reasons. Speaking with Tagesspiegel, he estimated the probability of reaching Mars alive at only 30%, and that of surviving there more than three months at less than 20%. He said, "They don't care what happens to those people in space... If my tax money were used for such a mission, I would organize a protest." Space tourist