ESA MARS Express Image: Rim of Schiaparelli impact basin

The small crater embedded in the northwestern rim of the Schiaparelli impact basin features prominently in this new image from ESA’s Mars Express.

All around is evidence for past water and the great martian winds that periodically blow.

Schiaparelli is a large impact basin about 460 km in diameter located in the eastern Terra Meridiani region of the equator of Mars.

The centre of the basin lies at about 3°S/17°E and is named after the Italian astronomer Giovanni Schiaparelli (1835–1910). Although he also studied Mercury and Venus, he is best known for his observations of the Red Planet.

During the ‘Great Opposition’ of 1877, when Mars passed close to Earth, Schiaparelli mapped the planet, perceiving a number of straight dark lines across the red surface.

He assumed that these were natural water-filled channels and used the equivalent Italian word, ‘canali’.

However, other astronomers thought he meant canals, meaning artificial irrigation and transportation routes, which led to a few astronomers, and a large number of the general public, believing that they had been created by intelligent Martians.

Now we know that Schiaparelli’s ‘canali’ were illusions created by the comparatively poor telescopes of the time and there are no water-filled channels on Mars today. Nevertheless, there is evidence in this new picture that water was once present in this region of the planet, perhaps in the form of a lake.