The tiny moons of Mars Among the nine planets in our Solar System, the four nearest the Sun are referred to as terrestrial.
Earth is third from the Sun and Mars is fourth.
Among the four terrestrial planets, only Earth and Mars have natural satellites. Earth has its Moon. Mars has two tiny natural satellites, Phobos and Deimos, named after the horses of the mythical Roman god of war, Mars. More than a century later, we know what Phobos looks like. Interplanetary probes have beamed photos of it to Earth.