Known Space -- Sol -- Mars -- | Phobos |
The potato-shaped Martian satellite is undoubtably a captured asteroid. Its nearly black surface is darker than asphalt. The largest crater on Phobos is Stickney, 8 km long (a third the size of Phobos). It had been hoped that Phobos might contain water, which would have been useful for the first Martian explorers, but this was not to be.
The orbit of Phobos is very low ... too low. It is constantly being pulled towards the Martian surface and in 100 million years it will crash.
Orbital Distance: 9,075 km - 9,465 km (average 9,270 km) Eccentricity: 0.021 Local Year: 0.319 days (7h 39m 21.6s) Orbital Velocity: 2.11 km/s (average) Inclination: 1.100° Local Day: 0.320 days (7h 40m 48s) Axial Tilt: n/a Diameter: 27 km x 22 km x 18 km (irregular) Composition: Carbonaceous rock Density: 1.94 g/cm3 Mass: 1.08 x 1013 tonnes (2/billion earths) Gravity: 0.001 G Escape Velocity: 0.011 km/s Area: 1,520 km2 Surface Material: Carbonaceous rock Atmosphere: None Pressure: None Albedo: 0.06 Temperature: ???°C |