Neptune


Data
30 AU
165 years to orbit the Sun
~16 hour rotation
A lot like Uranus
high albedo
low density
rocky core - 10 to 15x more massive than Earth
10 - 20% H and He

Differences
Uranus atmosphere is bland vs. many clouds lots of different things to observe
Uranus has no internal heat source vs Neptune's strong one (2.7x more than it receives)

Atmosphere
mostly H and He
some methane
appears bluish in a telescope - methane absorbs the red light
Great Dark Spot
in southern hemisphere
anticlyclonic - high pressure
size of the Earth
Scooter
Rings
occultation of a star - 1983
not sure if full rings or ring arcs
Vger 2 answers that question

Moons
Triton
Density - 2.07 g/cm3 so it is probably mostly rock
lots of water ice - tell by structure
some methane and ammonia ices
Varied surface features - craters, polar caps, cliffs, faults, ice volcanoes
Nitrogen atmosphere

Neried

Vger 2 discovered 6 more

The end of the solar system
heliopause - boundary of the hot solar wind (105 K) and cooler interstellar gas (104 K)
115 to 180 AU