Apparent retrograde motion notable on Mars which has two natural satellites, Phobos and Deimos. Both moons orbit Mars in an eastward (prograde) direction, however Deimos has an orbital period of 1.23 Martian sidereal days, making it supersynchronous, whereas Phobos has an orbital period of 0.31 Martian sidereal days making it subsynchronous. Consequently, although both moons are travelling in an eastward (prograde) direction, they appear to be travelling in opposite directions when viewed from the surface of Mars due to their orbital periods in relation to the rotational period of the planet. All other planetary bodies in the Solar System also appear to periodically
Mars One men and 50 women from the total pool of 660 from around the world were selected to move on to the third round of the astronaut selection process: Applicants were remotely interviewed and recorded by Mars One over a relatively short Skype/SparkHire call regarding Martian-related orbital, temp/pressure, geological and historical parameters and the specific elements of the Mars One one-way mission. Joseph Roche, one of the finalists, has accused the selection process of being based on a point system that is primarily dependent on how much money each individual generated or gave to the Mars One organization, despite many of