Mid latitude region of Jupiter, 1979.
© National Aeronautics & Space Administration / Science & Society
This photograph taken by Voyager 1 shows the longitudinal cloud patterns and eddies which are characteristic of the atmosphere of Jupiter. Jupiter's atmosphere is made up of 90 % hydrogen and almost 10 % helium, together with traces of other gases, including methane and ammonia. Immensely strong winds occur, and the storm clouds exhibit colours which are thought to be due to chemical reactions in the atmosphere. Unlike winds on Earth, which are caused by solar heating and condensation of water vapour, Jupiter's winds are believed to be driven by the planet's internal heat. The two Voyager spacecraft were launched in 1977 to explore the planets in the outer solar system. Voyager 1 flew past Jupiter at a distance of 278,000 kilometres in March 1979.