New Scientist: The diaphanous sheen of a butterfly wing? Or the exquisite iridescence of a soap bubble? Surprisingly, it's neither. This is a radar image snapped from low Earth orbit, showing the biggest glacier in the Arctic as its ice field inexorably grinds its way towards the open ocean. Radar images of the Petermann Glacier in Greenland, taken 24 days apart, were combined to create this colourful interferogram that highlights movement as small as a few centimetres. The rainbow interference fringes are widely...