Uranus with satellites Miranda, Ariel and Umbriel, from Voyager 2, 24 January 1986. Composite of images taken by the unmanned Voyager 2 spacecraft from 74 million kilometres (46 million miles) away, towards the illuminated south pole of Uranus. The blue colour is the result of atmospheric methane, which absorbs the red wavelengths from incoming sunlight. Three of Uranus' five known satellites are visible; Miranda (at far right, closest to the planet ), Ariel (top), and Umbriel (lower left).