An artwork of the terrestrial planet Mars set against the backdrop of the Milky Way. Mars's two moons, Phobos and Deimos, are seen passing in front. In this view of Mars we can see Valles Marineris in the middle - a vast chasm compared to which the US's Grand Canyon is little but a scratch. While off to the left we can see the Tharsis rise with its four giant volcanoes, the largest pf which (Olympus Mons) is the most massive volcano in the known Solar System.