Known Space -- Sol -- | Neptune |
The smallest and last of the four gas giants of the Solar system, Neptune lies 30 times Earth's distance from the Sun.
Neptune's core is a ball of molten rocky material slightly larger than the Earth, with a temperature of 7,000 degrees C. This core is surrounded by a layer of water and ammonia, which is in turn surrounded by a layer of hydrogen and helium. There is an upper cloud layer of methane ice, and a lower cloud layer of hydrogen sulfide ice.
The largest of Neptune's satellites, Triton, is slightly smaller than Luna. It's rocky surface is covered with a methane frost, and there is a slight methane atmosphere. It orbits Neptune backwards.
Orbital Distance: 29.800 AU - 30.316 AU (average 30.058 AU) Eccentricity: 0.009 Local Year: 60,190.30 days (164.8 years) Orbital Velocity: 5.43 km/s (average) Inclination: 1.572° Local Day: 0.671 day (16h 6m 0s) Axial Tilt: 28.800° Diameter: 50,538 km (cloud tops) Composition: n/a Density: 2.064 g/cm3 Mass: 1.03 x 1020 tonnes (17.20 earths) Gravity: 1.20 G Escape Velocity: 23.90 km/s Area: 8,024 million km2 Surface Material: n/a Atmosphere: Hydrogen, helium, and methane Pressure: ? Albedo: 0.35 Temperature: -220°C (cloud tops) |
Satellite Distance Month Day Diameter Naiad 48,000 km 0.296 d 0.296 d 0.004 Thalassa 50,000 km 0.312 d 0.312 d 0.006 Despina 52,500 km 0.333 d 0.333 d 0.014 Galatea 62,000 km 0.429 d 0.429 d 0.012 Larissa 73,600 km 0.554 d 0.554 d 0.015 Proteus 117,600 km 1.121 d 1.121 d 0.033 Triton 354,800 km 5.877 d 5.877 d 0.212 Nereid 5,514,000 km 360.160 d 360.160 d 0.019 |
Ring Distance from Neptune Width Galle 41,900 km 50 km La Verrier 53,200 km 50 km Plateau (or Lassell) 53,200 km - 59,100 km 4,000 km Arago 57,600 km 30 km Adams 62,900 km 50 km |