Phobos (moon) energy due to wind blowing dust off of its solar panels, took several short-exposure photographs of the night sky from the surface of Mars. Phobos and Deimos are both clearly visible in the photograph. The Soviet Union undertook the Phobos program with two probes, both launched successfully in July 1988. "Phobos 1" was accidentally shut down by an erroneous command from ground control issued in September 1988 and lost while the craft was still en route. "Phobos 2" arrived at the Mars system in January 1989 and, after transmitting a small amount of data and imagery but shortly before beginning
Planet that objects that fulfill the orbital zone clearance requirement automatically fulfill the roundness requirement. The table below lists Solar System bodies once considered to be planets. Beyond the scientific community, Pluto still holds cultural significance for many in the general public due to its historical classification as a planet from 1930 to 2006. A few astronomers, such as Alan Stern, consider dwarf planets and the larger moons to be planets, based on a purely geophysical definition of "planet". The names for the planets in the Western world are derived from the naming practices of the Romans, which ultimately derive from