Mars from Mariner 9, on 11 November 1971, as the spacecraft approached the planet. Parts of the day (right) and night (left) sides are seen. The smoothness of the surface is caused by a dust storm that has obscured surface features. Towards the bottom of the disc the south polar ice cap is seen as a slightly brighter area. This picture was taken at a distance of around 720,000 kilometres from Mars. Mariner 9 had been travelling for 6 months, and reached Mars on 13 November 1971, becoming the first spacecraft to orbit another planet. Previous Mars missions had only flown past the planet. It used television cameras to return pictures of the Martian surface to Earth, and studied the composition of the planet's atmosphere and surface.