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
Moons of Neptune orbit Neptune at an average of 125 times the distance between Earth and the Moon. Neptune has the largest Hill sphere in the Solar System, owing primarily to its large distance from the Sun; this allows it to retain control of such distant moons. Nevertheless, Jupiter's S/2003 J 2 orbits at the greatest percentage of the primary's Hill radius of all the moons in the Solar System on average, and the Jovian moons in the Carme and Pasiphae groups orbit at a greater percentage of their primary's Hill radius than Psamathe and Neso. The mass distribution of the Neptunian moons