Swains Island, located in the South Pacific Ocean, is a small coral atoll comprised of an outer perimeter (approximately 13 km in circumference) of flat coral reefs and a 2.5 km² ring-shaped landmass surrounding a shallow fresh-water lagoon in the centre that is closed off from the sea.

ESA’s Proba satellite acquired this image on 27 March 2006 with its Compact High Resolution Imaging Spectrometer (CHRIS), designed to acquire hyperspectral images with a spatial resolution of 17 metres across an area of 13 kilometres. Weighing just 14 kg, CHRIS is the smallest hyperspectral imager ever flown in space and can acquire up to five images at a time.