As if anyone knew impact craters had categories, an astronomer from Northern Arizona University has described a new one on the face of Mars: the Low-Aspect-Ratio Layered Ejecta (LARLE) craters. This discovery was made possible by the ability to capture high-resolution photos of Mars.

“That’s part of the fun of science, to see something and say, ‘Whoa, what’s that?’” said Nadine Barlow in a presentation she did this week at the American Astronomical Society Division for Planetary Sciences in Denver, Colo. “Projects like this end up leading to proposals.”

According to Barlow, she was examining high-resolution photos of Mars’ surface when she noticed something peculiar about the craters. The images were part of an attempt to update her catalog of Marian craters. “I had to ask, ‘What is going on here?’” Barlow said.

Barlow went to work researching “explosion literature” with a team of colleagues. She determined that a base surge— when a large explosion creates a cloud of fine material that pushes out along the surface where the eruption occurred—may have had something to do with the shape of the oval craters. These particular craters were also found at high latitude regions where thick, fine-grained sedimentary deposits and subsurface ice were.

“The combination helps vaporize the materials and create a base flow surge,” Barlow said. The low aspect ratio refers to how thin the deposits are relative to the area they cover.

The team was able to conduct this research with a stream of data currently flowing from the surveillance of Mars. The researchers were able to data from the older Mars Odyssey Orbiter a global survey, and then they used high-resolution images from the Mars Reconnaissance Orbiter for to more closely examine the Martian surface.

“We’re looking in more detail at these deposits to find out what their characteristics are,” Barlow said. “We can see dune-like structures and the hollows that occur in the outer deposit.” Barlow is planning to update her catalog and expects the finalized revision to be complete in about a year.

Launched in April 2001, the Mars Odyssey orbiter became the longest-serving Mars-based craft in 2010. The Odyssey has been NASA’s main communications channel for NASA’s ground-based assets and remains that for the Curiosity rover. The Mars Reconnaissance Orbiter was launched in 2005 for the purpose of creating a high-resolution map of the Martian surfaces, with a particular emphasis on finding potential landing sites.