1-157-367 - Oxford Science Archive/Heritage Images

Comet Shoemaker-Levy colliding with Jupiter, 20 July 1994. Between 16 and 22 July 1994, some 20 fragments of Comet Shoemaker-Levy 9 struck the atmosphere of Jupiter, creating disturbances such as the dark smudges visible on the upper part of the planet in this photograph. The largest impact released energy equivalent to an estimated 6 million megatons of TNT and left a mark in the Jovian atmosphere larger than the diameter of the Earth. Astronomers believe that Jupiter plays a vital role in intercepting cosmic debris that might otherwise have reached the inner solar system, enabling the unbroken development of life on Earth to have occurred.