A giant storm was at the origin of the beautiful spirals imprinted in Saturn’s atmosphere. This false-colour infrared image of the ringed planet was taken by NASA’s Cassini spacecraft, which has been in orbit about Saturn since July 2004 (CERN Courier September 2004 p13). Colours correspond to different heights in the atmosphere, from red, deep inside, to blue at the top. The view is taken from the plane of the rings (blue horizontal line), which cast their shadow on the planet’s southern hemisphere. The vortices in the northern hemisphere are atmospheric perturbations following the passage of a massive storm that moved from right to left and is hidden on the other side in this view taken in January 2011. Such giant storms on Saturn typically occur every 30 Earth years, or once every Saturn year. It was, however, a surprise to see one so early, well before Saturn’s summer solstice in 2017.
Image credits: NASA/JPL-Caltech/Space Science Institute.