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 for public viewing. Mars One initially estimated a one-way trip, excluding the cost of maintaining four astronauts on Mars until they die, at 6 billion USD. Lansdorp has declined questions regarding the cost estimate. A proposed global reality-TV show was intended to provide funds to finance the expedition, however, no such television show has emerged and no contracts have been signed. The astronaut selection process (with some public participation) was to be televised and continue on through the first years of living on Mars. Discussions between Endemol started in June 2014, producers of the "Big Brother" series, and Mars One