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Planetary Facts
These facts about the planets and the Moon were taken from two sources: JPL's HORIZONS ephemeris generator and the National Space Science Data Center's planetary fact sheets, which are probably based on the HORIZONS data. Diameters for the giant planets are at the 1-bar altitude. Orbital distances for the Moon are measured relative to Earth's center.
| Planetary Facts (Metric units) | |||||||||
| PHYSICAL PROPERTIES | Mercury | Venus | Earth | Moon | Mars | Jupiter | Saturn | Uranus | Neptune |
|---|---|---|---|---|---|---|---|---|---|
| Mean diameter (km) | 4879 | 12,104 | 12,742 | 3475 | 6780 | 139,822 | 116,464 | 50,724 | 49,248 |
| Equatorial & polar diameter (km) | 4879 | 12,104 | 12,756 12,714 |
3475 | 6792 6752 |
142,984 133,708 |
120,536 108,728 |
51,118 49,946 |
49,528 48,682 |
| Mass (1024kg) | 0.330 | 4.87 | 5.97 | 0.073 | 0.642 | 1899 | 568 | 86.8 | 102 |
| Density (kg/m3) | 5427 | 5243 | 5515 | 3340 | 3933 | 1326 | 687 | 1270 | 1638 |
| Gravity (m/s2) | 3.7 | 8.9 | 9.8 | 1.6 | 3.7 | 23.1 | 9.0 | 8.7 | 11.0 |
| Escape Velocity (km/s) | 4.3 | 10.4 | 11.2 | 2.4 | 5.0 | 59.5 | 35.5 | 21.3 | 23.5 |
| Hill sphere radius (planetary radii) | 94 | 167 | 235 | 320 | 740 | 1100 | 2700 | 4700 | |
| Mean Temperature (C) | 167 | 464 | 15 | -20 | -65 | -110 | -140 | -195 | -200 |
| Geometric albedo | 0.106 | 0.65 | 0.37 | 0.12 | 0.15 | 0.52 | 0.47 | 0.51 | 0.41 |
| Surface Pressure (bars) | 0 | 92 | 1 | 0 | 0.01 | Unknown* | Unknown* | Unknown* | Unknown* |
| ORBITAL MOTION | Mercury | Venus | Earth | Moon | Mars | Jupiter | Saturn | Uranus | Neptune |
| Rotation Period (hours) | 1407.6 | -5832.5 | 23.9 | 655.7 | 24.6 | 9.9 | 10.7 | -17.2 | 16.1 |
| Length of Day (hours) | 4222.6 | 2802.0 | 24.0 | 708.7 | 24.7 | 9.9 | 10.7 | 17.2 | 16.1 |
| Distance from Sun (106 km) | 57.9 | 108.2 | 149.6 | 0.384* | 227.9 | 778.6 | 1433.5 | 2872.5 | 4495.1 |
| Perihelion (106 km) | 46.0 | 107.5 | 147.1 | 0.363* | 206.6 | 740.5 | 1352.6 | 2741.3 | 4444.5 |
| Aphelion (106 km) | 69.8 | 108.9 | 152.1 | 0.406* | 249.2 | 816.6 | 1514.5 | 3003.6 | 4545.7 |
| Orbital Period (days) | 88.0 | 224.7 | 365.2 | 27.3 | 687.0 | 4331 | 10,747 | 30,589 | 59,800 |
| Orbital Velocity (km/s) | 47.9 | 35.0 | 29.8 | 1.0 | 24.1 | 13.1 | 9.7 | 6.8 | 5.4 |
| Orbital Inclination (degrees) | 7.0 | 3.4 | 0.0 | 5.1 | 1.9 | 1.3 | 2.5 | 0.8 | 1.8 |
| Orbital Eccentricity | 0.205 | 0.007 | 0.017 | 0.055 | 0.094 | 0.049 | 0.057 | 0.046 | 0.011 |
| Axial Tilt (degrees) | 0.01 | 177.4 | 23.4 | 6.7 | 25.2 | 3.1 | 26.7 | 97.8 | 28.3 |
