Phobos (moon) - Wikipedia
Phobos is a small, irregularly shaped object with a mean radius of 11 km (7 mi). It orbits 6,000 km (3,700 mi) from the Martian surface, closer to its primary body than any other known natural satellite to a planet. It orbits Mars much faster than Mars rotates and completes an orbit in just 7 hours and 39 minutes.
Moons of Mars - Wikipedia
The moons of Mars may have started with a huge collision with a protoplanet one third the mass of Mars that formed a ring around Mars. The inner part of the ring formed a large moon. Gravitational interactions between this moon and the outer ring formed Phobos and Deimos.
Phobos - NASA Science
Phobos is the larger of Mars' two moons and is 17 x 14 x 11 miles (27 by 22 by 18 kilometers) in diameter. It orbits Mars three times a day, and is so close to the planet's surface that in some locations on Mars it cannot always be seen.
Phobos: Facts About the Doomed Martian Moon | Space
Dec 8, 2017 · But Phobos won't zip around Mars forever. The doomed moon is spiraling inward at a rate of 1.8 centimeters (seven-tenths of an inch) per year, or 1.8 meters (about 6 feet) each century.
Mars' Moons: Facts About Phobos & Deimos | Space
Dec 8, 2017 · Phobos has the closest orbit to its primary of any moon in the solar system, but still only appears a third as wide as Earth's full moon. Phobos orbits only 3,700 miles (6,000 km) from the...
Moons of Mars - Science@NASA
Phobos is the larger of Mars' two moons. It orbits Mars three times a day, and is so close to the planet's surface that in some locations on Mars it cannot always be seen. Phobos is nearing Mars at a rate of six feet (1.8 meters) every hundred years.
Mars Moons: Facts - Science@NASA
Mars' moons are among the smallest in the solar system. Phobos is a bit larger than Deimos, and orbits only 3,700 miles (6,000 kilometers) above the Martian surface. No known moon orbits closer to its planet.
Mars’ Moon Phobos is Slowly Falling Apart - NASA
Nov 10, 2015 · The long, shallow grooves lining the surface of Phobos are likely early signs of the structural failure that will ultimately destroy this moon of Mars. Orbiting a mere 3,700 miles (6,000 kilometers) above the surface of Mars, Phobos is closer to …
Phobos | Orbit & Surface Features | Britannica
Phobos, the inner and larger of the two moons of Mars, in a composite of photographs taken by the Viking 1 orbiter in October 1978 from a distance of about 600 km (370 miles). The most prominent feature is the impact crater Stickney, which is almost half as wide as the moon itself.
In Depth | Phobos – NASA Solar System Exploration
Phobos is the larger of Mars' two moons and is 17 x 14 x 11 miles (27 by 22 by 18 kilometers) in diameter. It orbits Mars three times a day, and is so close to the planet's surface that in some locations on Mars it cannot always be seen.