SATELLITES OF MARS.
| Name. | Discoverer. | Mean distance from Mars. Miles. | Sidereal period. d. h. m. | Diameter. Miles. | Maximum elongation. ″ | Apparent star magnitude. | |
|---|---|---|---|---|---|---|---|
| 1. PHOBOS | A. Hall, August 17, 1877. | 6,000 | 0 7 39 | 7 | 12 | 11½ | |
| 2. DEIMOS | A. Hall, August 11, 1877. | 15,000 | 1 6 18 | 6 | 32 | 13½ |