Exploration of Mars space probe to orbit another planet when it entered into orbit around Mars. The amount of data returned by probes increased dramatically as technology improved. The first to contact the surface were two Soviet probes: Mars 2 lander on November 27 and Mars 3 lander on December 2, 1971Mars 2 failed during descent and Mars 3 about twenty seconds after the first Martian soft landing. Mars 6 failed during descent but did return some corrupted atmospheric data in 1974. The Soviet probes Phobos 1 and 2 were sent to Mars in 1988 to study Mars and its two moons, with
Moons of Haumea pure crystalline water ice covering much of its surface. The unusual spectrum, and its similarity to absorption lines in the spectrum of Haumea, led Brown and colleagues to conclude that it was unlikely that the system of moons was formed by the gravitational capture of passing Kuiper belt objects into orbit around the dwarf planet: instead, the Haumean moons must be fragments of Haumea itself. The sizes of both moons are calculated with the assumption that they have the same infrared albedo as Haumea, which is reasonable as their spectra show them to have the same surface composition. Haumea's albedo