Mars-Orbiting Spacecraft Captures ‘Snaking Scar’ Across the Base of Enormous Volcano

A high-resolution camera system aboard the Mars Express Orbiter has returned stunning images of “snaking” gashes across the foot of Arsia Mons, one of the red planet’s massive volcanoes.

The European Space Agency (ESA) clocked Mars’ deep, uneven scar at roughly 373 miles long (600 km) — making it around one-and-a-third times the length of the Grand Canyon. Humans first documented the feature in 1930, and formally dubbed it Aganippe Fossa 46 years later.

“The structure, named after a spring nymph in Greek mythology, puzzles even today’s experts,” said the German Aerospace Center, which developed the stereo camera aboard the 21-year-old Mars Express spacecraft. The agency added, “Some theories suggest that the trench is tectonic in origin, while others claim that volcanic veins formed during a late period of activity,” creating scar-like depressions across both rocky and gently sloping terrain.

For its part, the ESA said Aganippe Fossa likely developed as “magma rising underneath the colossal mass of the [nearby] Tharsis volcanoes caused Mars’s crust to stretch and crack.”

In addition to the base of Arsia Mons — which stretches about 2 km higher than Earth’s tallest volcano — Aganippe Fossa’s gashes cross through gigantic, marble-like patterns created via “windblown dust and sand,” according to the ESA.

The agency captured the feature stereoscopically, which means you can view it (and its neighboring volcano) in 3D, if you happen to have red-blue or red-green glasses handy.