A Nasa-led mission to map the Sun's surface has produced the world's first ever three dimensional image of the star. Two satellites orbiting the Sun perfectly aligned on opposite sides for the first time taking images that when combined create the most complete picture ever of its surface. The Solar Terrestrial Relations Observatory (STEREO) mission, led by Nasa, launched its two satellites in 2006 and they have been orbiting the Sun ever since. The two satellites are travelling at different speeds and so every few years they achieve 180 degrees of separation on exactly opposite sides of the Sun.

Credit : NASA / REUTERS