Five to seven years of this, with each bit of the sky being recorded in five different colours, should be enough to complete coverage of a quarter of the sky.

ECONOMIST: The Sloan star survey: An intergalactic cruise | The

Hike mountain trails or simply stroll the narrow roads and watch the colours of the sky and lakes change throughout the day.

BBC: In Mayo, quintessential Ireland holds on

The team went on to use data from a range of other telescopes including the Very Large Telescope, the Two Micron All-Sky Survey and the Spitzer space telescope - each of which sees in a particular set of colours, in turn evidencing stars of varying ages.

BBC: Galaxy crash sparks biggest spiral

And the sky is blue, it says, because the sun produces white light which is made up of all the colours of the rainbow.

BBC: rainbow