Ever since the Pioneer and Voyager missions to the outer planets in the late 70s and early 80s, planetary scientists have known about Saturn’s aurorae. Hubble Space Telescope scientists have tracked the eerie glows over the past decade and a half using ultraviolet filters and instruments to study the characteristics of these emissions-related events. Recent studies using the Hubble Space Telescope and Cassini spacecraft show that the dancing light of the auroras on Saturn behaves in ways different from how scientists have thought possible for the last 25 years.
To get the image above, astronomers combined HST and Cassini ultraviolet images of Saturn’s southern polar region with visible-light images of the planet and its rings to make this picture. The auroral display appears blue because of the glow of ultraviolet light. In reality, the aurora would appear red to an observer at Saturn because of the presence of glowing hydrogen in the atmosphere. On Earth, charged particles from the Sun collide with nitrogen and oxygen in the upper atmosphere, creating auroral displays colored mostly green and blue.
If you click on the link above, you’ll see a “movie” of the Saturnian aurorae,dancing around the auroral “oval” at one of the planets’ poles. For more pictures and videos, visit the European Space Agency’s Hubble releases page.
