ESA’s Mars Express Orbiter Captures Massive Scar-Like Canyon on the Red Planet; Experts Investigate the Origin of Aganippe Fossa

The European Space Agency's Mars Express Orbiter has photographed a large scar carved into the surface of Mars in never-before-seen detail.

Mysterious Giant Scar

Known as Aganippe Fossa, the giant canyon stretches up to about 375 miles across the surface of Mars, making it larger than the Grand Canyon, which is 277 miles long. The Martian valley was first observed by astronomers as early as 1930 but was named officially in 1976.

The new images were taken in high definition by the ESA's Mars Express Orbiter on December 13, 2023. This orbiter has made several crucial discoveries, like detecting water ice at the pole of the planet and methane production in the atmosphere.

Aganippe Fossa is located in the Tharsis region of Mars, along the flanks of Arsia Mons, one of the huge volcanoes on Mars. With a height of 12 miles, Arsia Mons is one of the three volcanoes that comprise the Tharsis Montes, the other two being Ascraeus Mons and Pavonis Mons.

According to ESA, the Aganippe Fossa is known as a graben-an elongated depression or ditch-like groove with steep sides on either side. The space agency also describes it as an uneven, dark scar slicing through marbled ground at the foot of a giant volcano.

One of the most interesting things in the captured image is the landscape surrounding a giant crack, varying on its either side. Land to the left appears very uneven and has several mounds, grooves, and ridges; to the right, the land looks smooth and is painted with "zebra-like" rocky stripes.

While there are plenty of "scars" on Mars, very few have been viewed with such great resolution.

Despite its enormous size, Aganippe Fossa shows comparable minute dimensions relative to Valles Marineris, which is considered the largest valley in the solar system and is also located on Mars. The gigantic canyon is nearly 2,5000 miles long, over 100 miles wide, and up to 5 miles deep.

The name Aganippe Fossa was derived from classical mythology. Aganippe is a nymph associated with a spring located at the foot of Mount Helicon in Greece. It was the daughter of the river Termessos. On the other hand, the word "Fossa" was derived from the Latin meaning ditch or trench- an elongated narrow depression on the surface of a planet or moon.

Astronomers studying the geology and tectonic history of Mars show interest in strange features like Aganippe Fossa. This is because these structures help them gain insight into the past geological processes that have shaped the surface of Mars over millions of years.

How Did Aganippe Fossa Form?

Scientists can't fully explain how Aganippe Fossa was formed. In a recent press release, however, ESA officials suggest that it may be a result of a large plume of magma that pooled underneath Arsia Mons long ago. The magma would have pushed the crust upwards and torn apart the Martian surface.

This event might have occurred as recently as 50 million years ago, at a time when Arsia Mons was believed to have stopped its eruptions. Recent evidence has suggested that Mars might have been volcanically active as early as 50,000 years ago.