This is one of the first images received from Sentinel-3A’s Sea and Land Surface Temperature Radiometer (SLSTR). Acquired with the instrument’s visible channels on 2 March 2016 at 10:04 GMT, this false-colour image features a large part of Europe showing vegetated areas in red. Moreover, the image demonstrates the instrument’s 1400 km-wide swath. The image also clearly shows storm Jake over the UK. As the SLSTR scans Earth’s surface, it senses visible light and infrared light (heat) in a number of different spectral channels. However, the thermal infrared channels will soon be working when the instrument has finished outgassing water vapour. This is necessary because the infrared channels must be cooled to operate properly. Once operational, the thermal-infrared channels will measure global sea- and land-surface temperatures every day to an accuracy of better than 0.3ºC.