Earth's atmosphere from space. This side-on view of the Earth's atmosphere shows a blue haze separating space (left) from a cloud-covered Earth. Most of the atmosphere is contained in a region extending to a height of 11 kilometres above the surface. After that, the air fades out into the blackness of space at an altitude of around 100 kilometres. The diameter of the Earth, in comparison, is around 12,600 kilometres. The blue haze is due to the scattering of light in the atmosphere. This photograph was taken by an astronaut on the International Space Station (ISS), over 300 kilometres above the Earth. It was taken on 17 December 2006, during mission STS-116.