Mars is a world of extremes. Not only does it have the largest volcano in the solar system (Olympus Mons), but it’s also home to the deepest known canyon, called Valles Marineris. The European Space Agency (ESA) recently captured new images of this grander canyon. The ESA didn’t need a fancy new mission to snap these images either. You can thank the venerable Mars Express orbiter, which has been in service for almost 20 years.
Mars Express captured the stunning new images on its 23,123th orbit of the red planet. Using its High Resolution Stereo Camera, the probe captured so much detail the images could be confused with aerial shots. The team generated photos of a region toward the western end known as Tithonium Chasma. This is one of two giant rifts that merge together to form the widest section of the canyon.
The Tithonium Chasma trench by itself is more than 500 miles long. Above, you can see patches of dark sand near the top of the rift. The team believes this may have come from past volcanic activity in the Tarsis region. Below is a second view from “inside” the canyon, depicting two lighter mounds on the floor of the canyon, but they’re more like heavily eroded mountains. The scale is hard to grasp, but these gentle “hills” rise almost two miles (3000 meters) above the canyon floor. Mars Express has detected water-bearing sulfate minerals in the bumpy region between the mounds.
Even if you’re not familiar with Valles Marineris by name, you’ve seen it if you’ve ever looked at an image of Mars. It’s the enormous gash near the equator, making it one of the planet’s most distinguishing features. Valles Marineris is 2,500 miles (400 kilometers) long, making it about the same width as the continental United States. In places, it slices more than four miles (7 kilometers) into the crust of Mars.
Comparing Valles Marineris to the Grand Canyon on Earth further illustrates how enormous this feature is. Despite having a “grand” right in the name, the Martian canyon is five times deeper and ten times longer. Scientists believe Valles Marineris reached this extreme scale because it was not carved by water like the Grand Canyon. Instead, it’s the result of tectonic plate movement, back when Mars was geologically active.
The aerial-style photos above can make it difficult to comprehend the scale of Valles Marineris, but take a look at the topographical map below. That scale is in kilometers. It also shows the path Mars Express took as it conducted the new observations.
It’s amazing to see a spacecraft continue to do science after so long. The ESA even worked recently to update the probe’s software, which was no simple feat as the original development was based on Windows 98.