Uranus Facts
| Discoverer: | Sir William Herschel (1781) |
| Spacecraft Encounter(s): | Voyager 2 (1986) |
| Mean distance from Sun: | 19.19 AU (2.871 billion km/1.784 billion mi) |
| Length of year: | 84.01 Earth years |
| Rotation period: | 17.24 hours |
| Mean orbital velocity: | 6.81 km/s (4.2 m/s) |
| Inclination of axis: | 97.92° |
| Diameter: | 51,118 km (31,765 mi) |
| Number of Observed Satellites: | >20 |
Comparisons with Earth:
| Diameter: | 4.0 x Earth's |
| Mean Distance from Sun: | 19.2 x Earth's |
| Mass: | 14.5 x Earth's |
| Density: | 0.22 x Earth's |
The Seasons of Uranus
Uranus' axis of rotation is tilted nearly 98° , almost perpendicular to its orbit. Consequently, the seasons and days on Uranus are strange. At times, the north pole points toward the Sun. At other times the south pole does.
The South Pole of Uranus
 NASA Press Release #P-29478 |
As Voyager 2 approached Uranus in January 1986, cameras recorded the planet as it would be seen by human eyes (left). After the image is enhanced, slight variations in the upper atmosphere cause concentric banding around the south pole (right). |
| The blue-green natural color of the planet is the color of the methane gas that comprises the atmosphere. | |
All information and images on this page were obtained from the National Air and Space Museum.