Double Aurorae on Saturn

The planet Saturn takes thirty Earth-years to orbit the sun, which means that its equinoxes happen only once every fifteen years. One of those equinoxes happened last September, and astronomers took the opportunity to focus the Hubble telescope on the planet to photograph it with both poles visible at once, and equally illuminated by the sun. The result is this image, which shows two simultaneous aurorae (!) on the poles of the distant gas giant:



Hubble captured a series of images like this one to assemble a short film of the aurorae, which are helping scientists to better understand Saturn's magnetic fields. "Given the rarity of such an event," comments ScienceDaily, "this new footage will likely be the last and best equinox movie that Hubble captures of our planetary neighbour."