- The Curiosity rover on Mars has been exploring the ancient channel Gediz Vallis for the past year. The channel is on Mount Sharp, the high point in the midst of Mars’ Gale crater, where Curiosity – a robot on wheels – has been exploring since 2012.
- An intriguing geologic formation resembling giant spiderwebs on Mount Sharp is the rover’s next destination. Curiosity will soon start rolling toward it.
- The ridges in the formation span several miles. How did they form? Scientists say that ancient Mars water holds the key and that salty mineral-ridge water likely evaporated and left the ridges behind when softer rock around them eroded away.
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NASA’s Curiosity rover on Mars has been busy studying the Gediz Vallis channel on Mount Sharp in Gale crater for the past year. Scientists say that either an ancient river or debris flows likely carved the channel eons ago. It was here that the rover found stones containing pure sulfur crystals, which the mission team is still puzzling over. Now, Curiosity is ready to begin the next phase of its journey.
NASA said this month that Curiosity will soon begin traveling to an intriguing set of web-like patterns called boxwork. The boxwork formations look like giant spiderwebs or honeycombs, extending for miles on Mount Sharp. They likely formed as the last remaining surface water in this part of Mars dried up.
The rover also took a stunning 360-degree panoramic image looking back at Gediz Vallis. See the panorama below.
Geological ‘spiderwebs’ on Mars
Currently, Curiosity is traveling along the western edge of Gediz Vallis. It will take a few more panoramic images before heading to the boxwork. The boxwork is a geological formation of intersecting ridges stretching for miles. It spans across 6 to 12 miles (10 to 20 km). As seen from above, it looks like giant spiderwebs, though of course it’s a geologic feature, not created by giant spiders. But did life play a role in its formation?
So how did these “spiderwebs” form? Mars is a dry desert today, but it apparently once had liquid water on its surface. The boxwork probably resulted from the last water in this region disappearing. As scientists have explained it, the water carried minerals into fractures in surface rock. Those minerals later hardened and cemented themselves in the fractures. The surrounding rock was softer and gradually eroded away, leaving behind the now-hardened fractures as intersecting ridges.
Such boxwork exists on Earth as well. But it is typically seen in caves and on cliff faces. But on Mars, the boxwork sprawls across the landscape.
It’s also possible living microbes once lived here, billions of years ago. On the early Earth, microorganisms thrived in similar conditions with salty, mineralized water. As Curiosity scientist Kirsten Siebach at Rice University in Houston, Texas, said:
These ridges will include minerals that crystallized underground, where it would have been warmer, with salty liquid water flowing through. Early Earth microbes could have survived in a similar environment. That makes this an exciting place to explore.
Gediz Vallis channel: a region of Mars that could have had rivers, wet debris flows, and dry avalanches billions of years ago.@MarsCuriosity snapped this image before departing the channel, an area that’s given the team plenty of puzzles to investigate: pic.twitter.com/PGfXd57LjU
— NASA JPL (@NASAJPL) November 19, 2024
Unusual sulfur rocks
Last July, NASA reported that Curiosity had discovered something never seen before on Mars: rocks containing crystals of pure sulfur. The rover found them in the Gediz Vallis channel. When Curiosity rolled over one of the stones, the wheel crushed it, revealing yellow crystals inside. What were they made of? As it turned out, the answer was pure sulfur. On Earth, pure sulfur can be associated with volcanic activity and hot springs. But the mission team hasn’t seen evidence of either of those explanations yet. It has, however, found evidence for ancient rivers, wet debris flows and dry avalanches, as well as the lake that once filled Gale crater.
So as of now, mission scientists don’t know how the pure sulfur formed there. As Curiosity project scientist Ashwin Vasavada at NASA’s Jet Propulsion Laboratory in Southern California noted:
We looked at the sulfur field from every angle – from the top and the side – and looked for anything mixed with the sulfur that might give us clues as to how it formed. We’ve gathered a ton of data, and now we have a fun puzzle to solve.
*Cronch* I ran over a rock and found crystals inside!
It’s pure sulfur. (And no, it doesn’t smell.) Elemental sulfur is something we’ve never seen before on Mars. We don’t know much about these yellow crystals yet, but my team is excited to investigate. pic.twitter.com/coIqWWGGJq
— Curiosity Rover (@MarsCuriosity) July 18, 2024
Bottom line: NASA’s Mars rover Curiosity is ready to leave an ancient river channel it’s been exploring. Next, it’ll go to a geological formation resembling giant spiderwebs.
Via NASA/JPL
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