The planet Jupiter, showing two of its moons and the Great Red Spot, 1979.
© National Aeronautics & Space Administration / Science & Society
Taken from 20 million kilometres away by Voyager 1, this picture shows the Great Red Spot, and two of Jupiter's four main moons; Io, which is above the Great Red Spot, and Europa. NASA launched two Voyager spacecraft in 1977 to explore the planets in the outer solar system. Voyager 1 flew past Jupiter at 278,000 kilometres in March 1979 before going on to pas Saturn in 1980. The largest planet in the solar system, Jupiter is a type of planet known as a gas giant, with an atmosphere composed mainly of hydrogen and helium. The atmosphere contains a number of large storms, the most famous of which, the Great Red Spot, is larger than the Earth and has been in existence for at least 300 years.