Mars was sliced open, leaving a scar on its surface. We don’t know how

The scar, known as Aganippe Fossa, is longer than the Grand Canyon (Picture: ESA/DLR/FU Berlin/SWNS)

Scientists have finally been able to get up close to a mysterious scar stretching across Mars – but still do not know how it got there.

The incredible feature, longer than the Grand Canyon at roughly 370 miles, has been captured by the European Space Agency (ESA) orbiter Mars Express.

It is also known as a ‘graben’, a ditch-like groove with steep walls on either side.

The scar, known as Aganippe Fossa, cuts across the lower region of one of the Red Planet’s largest volcanoes, Arsia Mons.

The ravine was first spotted in 1930, but this is the first time scientists have been able to see it up close.

ESA describes it as ‘a dark, uneven scar slicing through marbled ground at the foot of a giant volcano’ and ‘a ditch-like groove with steep walls on either side’.

The scar was first spotted from Earth in 1930 (Picture: ESA/SWNS)

The space agency say Mars Express regularly observes Arsia Mons and its nearby companions in the region of Tharsis, where several of Mars’s behemoth volcanoes are found.

This includes Olympus Mons, the tallest volcano in the solar system, at 18.6 miles high – around two and a half times the height of Mount Everest.

Arsia Mons itself measures 270 miles in diameter and rises more than five miles above the surrounding plains.

Mars Express has been exploring the planet since 2003 (Picture: ESA/Alex Lutkus/SWNS)

The ESA said: ‘We’re still unsure of how and when Aganippe Fossa came to be, but it seems likely that it was formed as magma rising underneath the colossal mass of the Tharsis volcanoes caused Mars’s crust to stretch and crack.’

Mars Express has been orbiting the Red Planet since 2003. It is imaging Mars’s surface, mapping its minerals, identifying the composition and circulation of its tenuous atmosphere, probing beneath its crust, and exploring how various phenomena interact in the martian environment.

Last year, images captured by the spacecraft helped create a stunning video ‘flying’ across the planet’s Noctis Labyrinthus, or ‘labyrinth of night’, a vast system of deep, steep valleys that stretches more than 700 miles on Mars – which is longer than Italy.

It also snapped images showing what the Earth and the Moon look like from the Red Planet.