Astronomy |
Planets -
Neptune |
| |
Bulk Parameters | Orbital Parameters
Observational Parameters | Atmospheric Parameters
Satellites |
| |
|
| |
| Bulk Parameters |
Black-Body Temperature |
33.2 K |
Bond Albedo |
0.82 |
Ellipticity |
0.017 1 |
Equatorial Radius (Defined by Pressure = 1 bar) |
24 766 km |
Escape Velocity |
23.5 km s−1 |
GM |
6.8351 × 106 km3 s−2 |
Mass |
102.43 × 1024 kg |
Mean Density |
1 638 kg m−3 |
Polar Radius (Defined by Pressure = 1 bar) |
24 342 km |
Solar Irradiance |
1.47 W m−2 |
Surface Gravity (At Pressure = 1 bar) |
11.00 m s−2 |
Visual Geometric Albedo |
0.41 |
Visual Magnitude |
−6.87 |
Volume |
6 254 × 1010 km3 |
Volumetric Mean Radius |
24 624 km |
|
|
| |
| Orbital Parameters |
Aphelion |
4 535.2 × 10 6 km |
Mean Orbital Velocity |
5.48 km s−1 |
Obliquity to Orbit |
29.56 ° |
Orbital Eccentricity |
0.008 59 |
Orbital Inclination |
1.769 ° |
Perihelion |
4 458.0 × 106 km |
Semimajor Axis |
4 498.3 × 106 km |
Sidereal Orbit Period |
60 189.0 days |
Sidereal Rotation Period (Magnetic Coordinates, determined by Voyager 2 Radio Science Experiment) |
16.11 hours |
Synodic Period |
367.49 days |
Tropical Orbit Period |
59 799.9 days |
|
|
| |
| Observational Parameters |
Apparent Magnitude near Opposition |
7.8 |
Maximum Apparent Diameter from Earth |
2.4 arc seconds |
Maximum Distance from Earth |
4 687.3 × 106 km |
Minimum Apparent Diameter from Earth |
2.2 arc seconds |
Minimum Distance from Earth |
4 305.9 × 106 km |
|
|
| |
| Atmospheric Parameters |
Average Temperature |
about 58 K |
Density at 1 bar |
about 0.45 kg m−3 |
Mean Molecular Weight |
2.53 g mol−1 to 2.69 g mol−1 |
Scale Height |
19.1 km to 20.3 km |
Surface Pressure |
Much more than 100 bars |
Temperature at 1 bar |
about 72 K |
Wind Speed |
0 to 200 m s−1 |
| Molecular Hydrogen H2 |
 |
80% |
| Helium He |
 |
19% |
| Methane CH4 |
 |
1.5% |
| Hydrogen Deuteride HD |
 |
105 ppm |
| Ethane C2H6 |
 |
1.5 ppm |
| Ammonia Ice |
 |
|
| Water Ice |
 |
|
| Ammonia Hydrosulphide |
 |
|
| Methane Ice |
 |
|
|
|
|
| |
|
|
[ H O M E ] [ S C I E N C E ] [ M A T H S ] [ A S T R O N O M Y ]
Download | Contact | About
|