David Bowie was on to something with his Spiders from Mars. While there are no crawling arachnids in residence on the red planet, there are spectacular landscape features known as “spiders.” NASA’s Mars Reconnaissance Orbiter peered down from above and captured a captivating view of what’s known as araneiform terrain. Araneiform means “spider-like.”
This story is part of Welcome to Mars, our series exploring the red planet.
The image comes from the HiRise (High Resolution Imaging Science Experiment) camera on MRO. HiRise is operated by a team based at the University of Arizona. The team highlights noteworthy images from the camera’s extensive archives in a Picture of the Day feature it calls HiPOD. The orbiter snapped the “spiders” crater view in May 2022. The image was the HiPOD on Thursday.
It shows a view into a crater with two notable features. One is the spidery dark formations that resemble a cluster of arachnids crawling over the landscape. The other is the geometric polygon shapes that look a lot like dried mud. “This image was acquired to study the influence of exposure to the sun’s rays on spider versus polygon development in terrain like this,” the HiRise team said.
This MRO HiRise image shows the “spider”-filled crater in context to a broader landscape.
NASA/JPL/University of Arizona
A wider view gives more context to what MRO was looking at. The crater pops out against the landscape.
The spiders tell a story of natural processes on Mars. The patterns come from the sublimation of ice below the surface. Sublimation is when a substance goes directly from a solid state to a gaseous state. These eye-catching formations have been spotted on other areas of Mars.
While the spiders capture the imagination, the polygon formations are also fascinating, even if they’re less flashy. Researchers have spotted similar forms in cold Earth environments subject to water freeze-thaw cycles. Martian polygons usually get their distinctive shape from raised ridges. The HiRise team said scientists can glean information about climate conditions and distribution of ice by studying polygons.
Science aside, the HiRise crater snapshot showcases the haunting beauty of Mars. This would be a great time to put on The Rise and Fall of Ziggy Stardust and the Spiders from Mars and stare into a crater from a planet far away.