Giant Lava Spirals Discovered on Mars: A Geologic First Outside of Earth

LOS ANGELES (The Blaze/AP) -- A researcher has spotted lava flows shaped like coils of rope spiraling near the equator of Mars, the first time such geologic features have been discovered outside of Earth.

These twisty volcanic patterns can be found on Hawaii's Big Island and in the Pacific seafloor on our planet. While evidence for lava flows is present in many places on Mars, none are shaped like this latest find.

"I was quite surprised and puzzled when I first saw the coils," Andrew Ryan, a graduate student at Arizona State University, said in an email. He reported the discovery in Friday's issue of the journal Science.

The biggest surprise? The largest Martian lava spiral measured 100 feet across -- bigger than any on Earth. It is further evidence that Mars was volcanically active recently -- geologically speaking within the past 20 million years.

For more than a decade, scientists debated whether this maze of valleys near the Martian equator was sculpted by ice or volcanic processes.

As part of a class project last year, Ryan analyzed about 100 high-resolution photos of the region snapped by the Mars Reconnaissance Orbiter, which has been photographing the Martian surface since 2006. One evening, while taking a second look at the images, Ryan zoomed in and noticed the lava coils. He counted 269 spirals ranging from 16 feet to 100 feet across.

Ryan said he was not surprised the features were overlooked in the past since they blended in with the terrain.

Space.com has more from Ryan:

"You can't see them unless you zoom in really close, and even then they're really subtle — it's pretty dusty there, so the images are just a pale gray color, and they don't really jump out until you boost the contrast, so it's not surprising at all to me that they've been overlooked before," Ryan said.

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These spirals resemble lava coils on Earth, such as those forming on the surface of Hawaiian lava flows. "These can only be explained by lava processes," Ryan said. "There are no known processes to twist ice around on that scale."

Planetary scientist David Paige of the University of California, Los Angeles, said the new work provides convincing evidence that the curious patterns were forged from volcanic activity.

This "illustrates just how complicated Mars' geologic history appears to really be," Paige wrote in an email. He was not part of the research team.

It's believed that rivers of molten lava flowed through the Martian valleys into a broad basin where they settled and formed the coil shapes. The spiral shapes were preserved as the lava cooled.

There are no clear signs that the region today is volcanically active. With more observations, Ryan said it is possible lava coils may exist elsewhere on the red planet.