The biggest known canyon in the slot Solar System is getting the star treatment in new images from the European Space Agency's Mars Express orbiter.As it whooshed by in Martian orbit, the spacecraft captured 

a pair of gouges in the planet's surface that make up part of the Valles Marineris, a system of canyons known as the Grand Canyon of Mars.

The Martian Grand Canyon, however, makes the Earth version seem like a canyon for ants.At 4,000 kilometers (2,485 miles) long and 200 miles wide, Valles Marineris is almost 10 times longer and 20 times 

wider than the vast canyon system found in North America. Earth has nothing that comes even close to comparing to Valles Marineris, which makes the feature intensely interesting to planetary scientists.