http://www.digitaljournal.com/article/360030

A new type of impact crater found on Mars

Posted Oct 10, 2013 by Nancy Houser
Nadine Barlow, professor of physics and astronomy at Northern Arizona University, has found a new type of impact crater on Mars — the Low-Aspect-Ratio Layered Ejecta (LARLE) Craters. She presented her findings at Denver's Division for Planetary Science
Photo: NASA/JPL-Caltech/MSSS/UA
Photo: NASA/JPL-Caltech/MSSS/UA
University of Arizona
Professor Barlow described the craters as a thin-layered outer deposit that extends well beyond the typical range of ejecta, The LARLE craters were discovered while she was studying high-resolution images, updating her catalog of Martian craters that will be completed in approximately one year. When she observed the new impact craters on Mars, she remarked, "I had to ask, 'What is going on here?'"
According to Science Daily, during the American Astronomical Society Division for Planetary Sciences in Denver, she stated, "lessons from underground nuclear tests and explosive volcanoes may hold the answer to how a category of unusual impact craters formed on Mars."
Impact craters are usually found at higher latitudes, correlating with sedimentary deposits that are thick and fine-grained, covered with subsurface ice. The low aspect ratio is connected to how thin the deposits are in relation to the coverage area.
"The combination helps vaporize the materials and create a base flow surge," Barlow said, in the Northern Arizon University article.
Professor Barlow, along with Boyce and Lionel Wilson of Lancaster University, have been studying the data stream from the ongoing surveillance of Mars. They also used older data from the Mars Odyssey Orbiter for a global survey, but the detailed work came from high-resolution images from the Mars Reconnaissance Orbiter.
"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."
According to the University of Arizona, Mars is an active planet, with scientists being able to study them right after the form.
Researchers from NASA and Universities have identified 248 new impact sites on Mars over the past ten years. They have used images from spacecraft to study when the impact craters appeared on the red planet. According to UANews, "The 200-per-year planetwide estimate is a calculation based on the number found in a systematic survey of a portion of the planet. "