A third giant red storm has flared up on Jupiter, joining the Great Red Spot and the recently developed Red Spot Junior. The spot, along with new measurements of record-high wind speeds on Red Spot Junior, come at a time when the solar system’s largest planet is experiencing a time of global upheaval.
Jupiter’s Great Red Spot is an ancient, hurricane-like storm that may have been raging for 340 years or more, based on early observations with telescopes. At three times the width of Earth, it is the largest storm in the solar system.
It was recently joined by a similar, but smaller storm called Red Spot Junior. Red Spot Junior grew out of the merger of three smaller, white storms between 1998 and 2000 and turned red in 2006. It is about the size of Earth.
Now, a third red spot, about half the size of Red Spot Junior, has broken out on the giant gaseous planet. The spot, previously a white storm, now appears red in Hubble Space Telescope images taken on 9 and 10 May. The observations were led by Imke de Pater of the University of California, Berkeley, US.
No one knows for sure what gives the three spots their red colour. But one theory is that especially violent storms dredge up material from deeper in Jupiter’s atmosphere, such as phosphorus-containing molecules, which undergo chemical reactions that turn them red when exposed to sunlight.