Uranus II
| Umbriel Statistics | |
|---|---|
| Discovered by | William Lassell |
| Date of discovery | 1851 |
| Mass (kg) | 1.27e+21 |
| Mass (Earth = 1) | 2.1252e-04 |
| Equatorial radius (km) | 584.7 |
| Equatorial radius (Earth = 1) | 9.1675e-02 |
| Mean density (gm/cm^3) | 1.52 |
| Mean distance from Uranus (km) | 265,970 |
| Rotational period (days) | 4.144177 |
| Orbital period (days) | 4.144177 |
| Mean orbital velocity (km/sec) | 4.67 |
| Orbital eccentricity | 0.0050 |
| Orbital inclination (degrees) | 0.36 |
| Escape velocity (km/sec) | 0.538 |
| Visual geometric albedo | 0.18 |
| Magnitude (Vo) | 14.81 |