Deimos (moon)
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| Discovery | |||||||
| Discovered by | Asaph Hall | ||||||
| Discovered in | 1877 | ||||||
| Orbital characteristics | |||||||
| Mean radius | 23,459 km | ||||||
| Eccentricity | 0.00033 | ||||||
| Revolution period | 1d 6h 17.9m | ||||||
| Inclination | 1.79° | ||||||
| Is a satellite of | Mars | ||||||
| Physical characteristics | |||||||
| Equatorial diameter | 15(×12.2×11) km | ||||||
| Surface area | km2 | ||||||
| Mass | 1.8×1015 kg | ||||||
| Mean density | 1.7 g/cm3 | ||||||
| Surface gravity | 0.00297 m/s2 | ||||||
| Surface Gravity (Earth = 1): | 3.031x10-4 | ||||||
| Rotation period | 1d 6h 17.9m | ||||||
| Axial tilt | ° | ||||||
| Albedo | 0.07 | ||||||
| Surface temp |
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| Atmospheric pressure | 0 kPa | ||||||
Deimos ("DEE mos") is the smaller and outermost of Mars' two moonss, named after Deimos from Greek Mythology. It is the smallest known moon in the solar system, though smaller undiscovered ones undoubtedly exist around the outer planets. Phobos and Deimos were both discovered by American astronomer Asaph Hall. Phobos was discovered on August 10, 1877.
Deimos is composed of carbon-rich rock, much like C-type (carbonaceous chondrite) asteroids, and ice. It is heavily cratered. It is probably an asteroid that was perturbed by Jupiter into an orbit that allowed it to be captured by Mars, though this theory is still in some dispute. Like most bodies of its size, Deimos is highly nonspherical with dimensions of 15×12.2×11 km.