 You'll recall that we covered Earth's aurora borealis in our segment on the heliosphere. The magnetosphere routes solar wind-charged particles to the poles that collide with the atmosphere there. The green and red colors are produced by excited oxygen and nitrogen atoms, respectively. Magnetospheres, and therefore auroras, exist on other planets in our solar system as well. Magnetospheres, using the Hubble Space Telescope, have taken a series of spectacular images featuring the fluttering auroras at Saturn's north pole. The observations were taken in ultraviolet light, and the resulting images from the excited hydrogen atoms provide us with the most comprehensive picture so far of Saturn's northern aurora.