13 Most Iconic Science Pictures Ever Taken

10. Untethered Space Walk

At the time that this photo was taken in 1984, astronaut Bruce McCandless was further out into open space than anyone had ever been - about 100 metres from the cargo bay.

The tiny little human set against the backdrop of black space and the blue of home certainly makes for a striking image.

Although terrifyingly untethered, McCandless was equipped with a Manned Maneuvering Unit (MMU) - a jetpack that works by shooting out jets of nitrogen.