Phobos 2 Phobos 2 Phobos 2 was the last space probe designed by the Soviet Union. It was designed to explore the moons of Mars, Phobos and Deimos. It was launched on 12 July 1988, and entered orbit on 29 January 1989. "Phobos 2" operated nominally throughout its cruise and Mars orbital insertion phases on 29 January 1989, gathering data on the Sun, interplanetary medium, Mars, and Phobos. "Phobos 2" investigated Mars surface and atmosphere and returned 37 images of Phobos with a resolution of up to 40 meters. Shortly before the final phase of the mission, during which the spacecraft was
Moons of Mars satellites, Earth had one and Jupiter had four (known at the time), that Mars by analogy must have two. Furthermore, as they had not yet been discovered, it was reasoned that they must be small and close to Mars. This would lead Swift to making a roughly accurate estimate of their orbital distances and revolution periods. In addition Swift could have been helped in his calculations by his friend, the mathematician John Arbuthnot. Voltaire's 1752 short story "Micromégas", about an alien visitor to Earth, also refers to two moons of Mars. Voltaire was presumably influenced by Swift. In recognition of