Description: In 1989 the space explorer Voyager 2 became the first manmade spacecraft to visit Neptune. Shortly thereafter, active geysers were discovered on it's largest moon, Triton. These geysers can reach heights of 8 km and blow the nitrogen they consist of up to 150 km away. Triton is a very cold place, and it holds many secrets. One of them is why it orbits Neptune backwards, in a retrograde orbit. The answer to this riddle may be that Triton is a captured moon from elsewhere in the solar system. Nevertheless, Triton's orbit is leading it closer and closer to Neptune. One day it will be crushed by Neptune's gravity, and form a ring system, much like Saturn's. In this illustration you see a small geyser, with Neptune and two other, much smaller moons Nereid and Proteus in the background. Also visible is some solar wind captured by Neptune's north pole, in the form of Aurora Borealis
