When the sun goes down the solar trees will return to their original position to give off a full spectrum of light to the street and pedestrians below.

By analysing data from a sensor that detects light in both the visible and the near-infra-red spectrum, a computer is able to determine the colour, type, shape and position of each item.

Using this hyperspectral data, scientists have mapped the location of sulfur deposits on the ice surface (red outline).