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LAWRENCE, Kan (AP) – Researchers at the University of Kansas have discovered a ferrous asteroid about a kilometer wide that allegedly crashed into Greenland maybe 12,000 years ago.
Details of the impact crater under the Hiawatha Glacier, in northwestern Greenland, were recently published in Science Advances, a multidisciplinary journal.
The crater – the first of any size under Greenland's icecap – is one of the 25 largest craters of impact on Earth. It is approximately 1,000 feet deep and more than 30 km in diameter, slightly larger than that of the capital Beltway in Washington State. according to a version of NASA.
John Paden, co-author of the report, is an associate professor of electrical engineering and computer science and a researcher at the KU Ice Plaque Remote Sensing Center (CReSIS).
Although Paden stated that the impact of the asteroid was not as cataclysmic as the asteroid of the "dinosaur" that hit the Yucatan Peninsula there are about 66 million of them. 39 years (1,000 times more massive), he left a huge crater hidden under the ice.
Although the impact crater report was released earlier this month, evidence of the crater's presence began to surface in 2015, the Lawrence Journal-World reported.
Scientists have collected radar survey data in Greenland for several decades, Paden said. Meanwhile, glaciologists have collected data sets that sound to the radar to produce maps of Greenland's nature under ice. They began to see large crater-like depressions and, as the site was at the edge of the ice cap, they also saw a circular pattern, said Paden.
Researchers studying the radar data suspected that it was a crater, but they still needed more data to confirm it, according to NASA's release.
It is there that CReSIS intervenes.
The center was used to build an ice-penetrating radar system that could accurately map the region. Paden himself participated in the development of the signal processing software for the radar system, called MCSRDS (Multichannel Collective Sounder Radar).
Carl Leuschen, Associate Professor of Electrical and Computer Engineering and Director of CReSIS, was also involved in the project; Rich Hale, Director of the KU Aerospace Engineering Department and Associate Director of CReSIS; and Fernando Rodriguez-Morales, professor of electrical engineering and computer science.
In May 2016, the KU team went to Greenland to explore the region. Rodriguez-Morales and Paden went to the field and carried out investigations at the impact crater site.
"To be part of it was a series of amazing events," Paden said.
"The crater is in a remote location very north of Greenland," he said. "We could hardly go because of the weather, we waited two weeks."
The fog was very bad most of the time in Greenland, which prevented them from flying. However, weather conditions improved towards the end of the trip and they were finally allowed to operate from Thule Air Base. They could do three days of flights.
"It was the exciting part of the trip," said Paden. "I did not think we would get data."
The crater was buried under the ice and it was hard to see from the plane. However, when the plane crossed the ledge where the ice bottom sank once upon the crater, they could see it.
"There was a visible edge on the ice plate – it was very unusual, almost a perfect half-circle," said Paden. "Once the NASA scientist, Joe MacGregor, spoke to me about it, it seemed obvious to me that it was a crater, and the detailed investigation showed confirmed."
MacGregor co-directed the research project with Danish scientist Kurt Kjaer.
"We were able to rest on the fact that it really had an impact crater shape," Paden said. "The pictures were so clear, there was no such thing as we saw."
In the statement from NASA, Kjaer noted that "the crater is exceptionally well preserved, which is surprising because glacier ice is an incredibly effective erosive agent that would have quickly eliminated traces of impact."
Kjaer said the state of the crater indicates that the impact may have occurred near the end of the last ice age, which would place the crater among the youngest on the planet.
Previous studies have shown that significant impacts can profoundly affect the Earth's climate, with major consequences for life on Earth at this time. The international research team plans to continue its work in this area, wondering when and how the impact of meteorites on the Hiawatha Glacier has affected the planet.
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