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 is divided among the seven payloads as follows: In 2022, a robotic rover was proposed to be launched to Mars in order to scout a landing site for the 2027 lander and a site for the Mars One colony. At the same time, a communication satellite would be launched, enabling continuous communication with the future landed assets. In 2024, six cargo missions were proposed to be in close succession, consisting of two living units, two life-support units, and two supply units. A spacecraft transporting four astronauts was proposed to meet a transit vehicle bound for Mars. In 2025, the landing