"Neptune was discovered by Urbain Le Verrier, John Couch Adams, and Johann Galle on 23 September 1846. It orbits around Sun 4.4983964 x 109 km away and is of 30.070 x Earth. Its Perihelion (closest) is 4.45975 x 109 km (2.981 x 101 A.U.), which is 30.318 x Earth. Its Aphelion (farthest) is 4.53704 x 109 km (3.033 x 101 A.U.), which is 29.830 x Earth. Neptune’s Sidereal Orbit Period (Length of Year) is 164.79132 Earth years, which is by comparison 164.791 x Earth. Its Orbit Circumference is 2.826 x 1010 km and by comparison 30.071 x Earth. It has an Average Orbit Velocity of 19,566 km/h (12,158 mph) which is 0.182 x Earth. Its Orbit Eccentricity is 0.00859048, which is 0.514 x Earth. It has an Orbit Inclination of 1.77 degrees. Its Equatorial Inclination to Orbit is 28.3 degrees. It has a Mean Radius of 2.4622 x 104 km, which is 3.8647 x Earth. Its Equatorial Circumference is 1.54705 x 105 km, which is 3.8647 x Earth. Its volume is 6.25257 x 1013 km3 and by comparison is 57.723 x Earth. Its mass is 1.0241 x 1026 kg, which is 17.148 x Earth. Its density is 1.638 g/cm3 , which is 0.297 x Earth. Its surface area is 7.6183 x 109 km2 and by comparison 14.980 x Earth. Its Surface Gravity is 11.15 m/s2 (36.6 ft/s2.) and by comparison if you weigh 100 pounds on Earth, you would weigh 114 pounds on Neptune. Its Escape Velocity is 2.356 x 104 m/s, which is by comparison: 2.105 x Earth. Its Sidereal Rotation Period (Length of Day) is 0.671 Earth days. The Effective Temperature on the planet is -214 °C (-353 °F) with the scientific notation of 59 K. The atmospheric constituents of Neptune are Hydrogen, Helium and Methane."