| Orbital Elements | ||
| ||
| Mean distance from Sun | 4,504,300,000 km | = 30.0611 astronomical units |
| Perihelion distance | 4,444,450,000 km | = 29.7093 astronomical units |
| Aphelion distance | 4,545,670,000 km | = 30.3859 astronomical units |
| Eccentricity of orbit | 0.0097 | |
| Inclination of orbit | 1.774° | relative to Earth's orbit |
| Period of orbit | 164.79 years | |
| Synodic period | 367 days | relative to Earth |
| Mean orbital speed | 5.45 km/s | |
| Minimum orbital speed | 5.37 km/s | |
| Maximum orbital speed | 5.50 km/s | |
| Physical Properties | ||
| ||
| Mean diameter | 49,248 km | = 3.86 Earth diameters |
| Equatorial radius | 24,746 km | |
| Oblateness | 1/40 | |
| Mass | 1.024 x 1026 kg | = 17.135 Earth masses |
| Mean density | 1.64 g/cm3 | |
| Rotational period | 16.11 hours | |
| Inclination of axis | 1.774° | relative to the axis of its orbit |
| Gravity at cloud tops | 11.0 m/s2 | |
| Escape speed | 23.5 km/s | from cloud tops |
| Visual geometric albedo | 0.41 | |
| Visual magnitude (Vo) | 7.84 | maximum, as seen from Earth |
| Temperature of visible clouds | -193 to -153°C | |
| Atmospheric pressure | 1 - 3 bars | at cloud tops |
| Atmospheric Composition | |
| |
| Hydrogen | 85% |
| Helium | 13% |
| Methane | 2% |
Moons
One large moon and at least ten small moons.
To my Space and Science home page
for more about the Solar System
Jeff Root
September 4, 2003