Mars Express provides truly epic views of the largest canyon in the Solar System

The largest known canyon in the Solar System is getting the star treatment in new images from the European Space Agency’s Mars Express orbiter.

While in Martian orbit, the spacecraft captured a pair of indentations in the planet’s surface that make up part of the Valles Marineris, a system of canyons known as the Grand Canyon of Mars.

However, the Grand Canyon of Mars makes the Earth version look like an ant canyon.

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 even compares to Valles Marineris, making the feature very interesting to planetary scientists.

The segmented images from Mars Express include sections of two chasmata, Ius on the left and Tithonium on the right. A close study of the details of these amazing natural structures can help scientists understand the geology and geological history of Mars.

The location of the two chasms. (NASA/MGS/MOLA Science Team)

For example, Mars appears to have already tectonically disappeared, with its crust fused into a single layer that covers the interior of the planet. This is unlike the Earth, whose crust is divided into plates that can move around with a whole range of consequences.

Scientists believe Valles Marineris formed when Mars had tectonic plates. Recent research suggests that the canyon system formed as a result of a widening rift between the plates a long time ago. This makes Valles Marineris very interesting indeed.

Images from Mars Express make the canyon appear relatively shallow, but the two chasmata are incredibly large; the full resolution version is approximately 25 kilometers per pixel. Ius Chasma stretches 840 kilometers in length in its entirety, and Tithonium Chasma 805 kilometers.

The orbiter is also equipped with 3D imaging capabilities, which reveal that in this image the canyon reaches as deep as it can go—about 7 kilometers, five times deeper than the Grand Canyon.

Topography of Ius and Tithonian ChasmataThe topography of the two chasms. (ESA/DLR/FU Berlin)

There are several features of note that the images reveal in both chasmata. Within Yus, a series of jagged mountains probably formed when the two tectonic plates moved apart. As it was some time ago, these mountains are quite eroded.

Titonium is partially colored in a darker shade at the top of the image. This may have come from the nearby volcanic region of Tharsis to the west of the chasm. Paler mounds arise from this dark sand; these are actually mountains that are over 3 kilometers high.

However, the tops of the mountains have been cleared by erosion. This suggests that whatever material the mountain is made of, it is softer and weaker than the rock around it.

However, this rock is not impenetrable either. In the lower right corner of the more visible part of the mountains, features suggest a recent landslide on the canyon wall to the right.

annotated map of chasmataAnnotated map showing various features in chasmata. (ESA/DLR/FU Berlin)

Interestingly, Mars Express found sulfate-bearing minerals in some of the elements in Tithonium Chasma. This has been interpreted as evidence that the Chasma was once (at least partially) filled with water.

The evidence is far from conclusive, but recent discoveries of hydrogen in the gap suggest that much of the water may be associated with minerals below the surface.

As with most science about Mars, it is difficult to draw conclusions with any certainty as we are forced – at least for now – to study it from a distance. But identifying areas of interest could help plan future Mars missions, both manned and unmanned; sending a rover to Valles Marineris would certainly help scientists answer some of the burning questions that have arisen.

Images like these are scientifically useful because they help frame and sometimes answer these questions. But they are also just incredibly beautiful.

The photos are published on the ESA website.

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