A mosaic of the 2,000-kilometer-long Valles Marineris canyon. The image is composed of 102 Viking Orbiter images, at a distance of 2500 kilometers from the surface.
A mosaic of the Schiaparelli Hemisphere of Mars, showing the Schiaparelli Crater, circa 1980.
This artist impression from the ESA shows Mars Express in orbit around Mars.
An artist's impression of the ExoMars 2020 rover exploring the surface of Mars.
A crater on Mars, estimated to be about 1 kilometer wide.
The European Space Agency (ESA) captures the Echus Chasma, one of the largest water source regions on Mars from ESA's Mars Express. It is still debated whether the valleys originate from precipitation, groundwater springs or liquid or magma flows on the surface.
Another angle of the Echus Chasma, from the ESA's Mars Express. The dark material shows a network of light-colored valleys that look similar to drainage networks known on Earth.
The Echus Chasma, one of the largest water source regions on Mars, as pictured from ESA's Mars Express. Scientists report that gigantic water falls may once have plunged over these cliffs on to the valley floor.
Taken from NASA's Mars Odyssey spacecraft, this composite image shows Mars' own Grand Canyon, Valles Marineris, on the surface of the planet. The Valles Marineris is 10 times longer, five times deeper and 20 times wider than Earth's Grand Canyon.
NASA's Mars Reconnaissance Orbiter captures the Garni Crater. The dark, narrow streaks are said to be formed by a flow of water on the surface of present-day Mars.