Neptune

Did You Know?
Large storms whirl through its upper atmosphere, and high-speed winds track around the planet at up 600 meters per second. One of the largest storms ever seen was recorded in 1989. It was called the Great Dark Spot. It lasted about five years.
Neptune has 14 moons. The most interesting moon is Triton, a frozen world that is spewing nitrogen ice and dust particles out from below its surface. It was likely captured by the gravitational pull of Neptune. It is probably the coldest world in the solar system.

Planet Profile
Mass (kg) 1.02 x 1026
Diameter (km) 49528
Mean density (kg/m3) 1640
Escape velocity (m/s) 23300
Average distance from Sun 30.07 AU (4,498,252,900 km)
Rotation period (length of day in Earth days) 0.67 (19.1 hours)
Revolution period (length of year in Earth days) 60,190 (164.8 Earth years)
Obliquity (tilt of axis degrees) 29.6
Orbit inclination (degrees) 1.77
Mean temperature (K) 48
Atmospheric components
  • 74% hydrogen,
  • 25% helium,
  • 1% methane (at depth)
Rings Rings are narrow, and contain concentrations of particles called ring arcs.