This is the Jovian equivalent of the Earth's Aurora Borealis and Aurora Australis. Aurorae occur when charged particles of the solar wind enter the upper atmosphere, making it glow. As on Earth, Jupiter's aurorae peak every 11 years at times of greatest solar activity and strongest solar winds. Aurorae occur around the poles because the stream of charged particles is attracted here by the planet's magnetic field. This flase-coloured ultraviolet image is from the Hubble Space Telescope.