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| Neptune Statistics |
| Discovered by | Johann Gotfried Galle |
| Date of discovery | September 23, 1846 |
| Mass (kg) | 1.024e+26 |
| Mass (Earth = 1) | 1.7135e+01 |
| Equatorial radius (km) | 24,746 |
| Equatorial radius (Earth = 1) | 3.8799e+00 |
| Mean density (gm/cm^3) | 1.64 |
| Mean distance from the Sun (km) | 4,504,300,000 |
| Mean distance from the Sun (Earth = 1) | 30.0611 |
| Rotational period (hours) | 16.11 |
| Orbital period around sun(years) | 164.79 |
| Mean orbital velocity (km/sec) | 5.45 |
| Orbital eccentricity | 0.0097 |
| Tilt of axis (degrees) | 28.31 |
| Orbital inclination (degrees) | 1.774 |
| Equatorial surface gravity (m/sec^2) | 11.0 |
| Equatorial escape velocity (km/sec) | 23.50 |
| Visual geometric albedo | 0.41 |
| Magnitude (Vo) | 7.84 |
| Mean cloud temperature | -193 to -153°C |
| Atmospheric pressure (bars) | 1-3 |
| Atmospheric composition |
Hydrogen 85% Helium 13% Methane 2% |