Largest canyon in the solar system revealed in stunning new images

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Largest canyon in the solar system revealed in stunning new images
By Brandon Specktor - Senior Writer 16 hours ago

It's nearly 10 times as long as the Grand Canyon, and three times as 
deep. But how did it form?

  A close-up photo of part of Mars' Valles Marineris, the single largest 
canyon in the solar system.
(Image: © NASA/JPL/University of Arizona)

About 87 million miles (140 million kilometers) above the Grand Canyon, 
an even larger, grander abyss cuts through the gut of the Red Planet. 
Known as Valles Marineris, this system of deep, vast canyons runs more 
than 2,500 miles (4,000 km) along the Martian equator, spanning nearly a 
quarter of the planet's circumference. This gash in the bedrock of Mars 
is nearly 10 times as long as Earth's Grand Canyon and three times 
deeper, making it the single largest canyon in the solar system — and, 
according to ongoing research from the University of Arizona (UA) in 
Tucson, one of the most mysterious.

Using an incredibly high-resolution camera called HiRISE (short for High 
Resolution Imaging Science Experiment) aboard the Mars Reconnaissance 
Orbiter, UA scientists have been taking close-up shots of the planet's 
strangest features since 2006. Despite some truly breathtaking images of 
Valles Marineris — like the one below, posted to the HiRISE website on 
Dec. 26, 2020 — scientists still aren't sure how the gargantuan canyon 
complex formed.

The Tithonium Chasma (part of Mars’ Valles Marineris) is slashed with 
diagonal lines of sediment that could indicate ancient cycles of 
freezing and melting. (Image credit: NASA/JPL/UArizona)

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Unlike Earth's Grand Canyon, Valles Marineris probably wasn't carved out 
by billions of years of rushing water; the Red Planet is too hot and dry 
to have ever accommodated a river large enough to slash through the 
crust like that — however, European Space Agency (ESA) researchers have 
said, there is evidence that flowing water may have deepened some of the 
canyon's existing channels hundreds of millions of years ago.

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A majority of the canyon probably cracked open billions of years 
earlier, when a nearby super-group of volcanoes known as the Tharsis 
region was first thrusting out of the Martian soil, the ESA said. As 
magma bubbled up beneath these monster volcanoes (which include Olympus 
Mons, the largest volcano in the solar system), the planet's crust 
easily could have stretched, ripped and finally collapsed into the 
troughs and valleys that make up Valles Marineris today, according to 
the ESA.

Evidence suggests that subsequent landslides, magma flows and, yes, even 
some ancient rivers probably contributed to the canyon's continued 
erosion over the following eons. Further analysis of high-resolution 
photos like these will help solve the puzzling origin story of the solar 
system's grandest canyon.

Originally published on Live Science.