NASA's MESSENGER probe collected numerous data from Mercury, mostly from the northern hemisphere of the planet. The surface of Mercury is displayed here in false colour to make its mineralogical components more visible. The rocks of Mercury’s surface have different reflection properties, which only become visible through the combination of images taken with different colour filters. Clearly visible is the volcanic rock-filled Caloris basin with a diameter of 1,500 kilometres. This makes it one of the largest impact craters on the planets and moons in the Solar System.