This image of Europe was taken by Sentinel-3A’s Ocean and Land Colour Instrument on 16 October 2016. The left part of the image shows, for example, how its 1270 km-wide swath captures an area stretching from Spain to Italy. The ‘zoom in’ on the right shows the French landscape in detail and changes in water colour off the south coast. The Ocean and Land Colour Instrument features 21 distinct bands in the 400–1020 μm spectral region tuned to specific ocean colour, vegetation and atmospheric correction measurement requirements. As well as its wide swath, it has a spatial resolution of 300 m for all measurements, overlapping the satellite’s Sea and Land Surface Temperature Radiometer swath.