Vesta asteroid surface. Satellite image of the surface of the giant asteroid Vesta, showing the flow of material (red and blue) inside and outside a crater called Aelia. This crater has a diameter of 4.3 kilometres and the exact origin of the flow structures is unknown. A possible explanation is that the impact that produced the crater could have created liquid material with different minerals than the surroundings. This image was created by assigning ratios of colour information collected from several colour filters in visible light and near-infrared light to maximise the subtle differences in lithology (the physical characteristics of rock units, such as colour, texture and composition). Image obtained by the framing camera on NASA's Dawn spacecraft