A feature on a planet that is markedly darker or brighter than its surroundings. Albedo features do not always correspond to a topographic or geological feature, as differences in albedo can arise from variations in surface composition as well as topography. For example, one of the darkest features on Mars seen through a telescope is Syrtis Major, but spacecraft have found no distinctive differences in topography or type of terrain between it and its surroundings. In general, though, albedo features are related to different terrain types, as on the Moon where the dark maria are plains of solidified lava and the bright spots are relatively recent impact craters.