Topography of the newly discovered Greenlandic crater. Image: NASA Goddard Space Flight Center
NASA has discovered a massive, ancient crater buried beneath two kilometers of ice in northwest Greenland. Even more amazing, it is the second crater discovered in recent months under the thick ice of the region.
The crater, which stretched 36.5 kilometers (22 miles), had probably been formed by an asteroid impact within the last 2.6 million years, published on Monday Geophysical Research Letters according to a study. If this feature turns out to be the effects of an asteroid attack, it is considered the 22nd largest impact crater on Earth.
Scientists have identified about 200 impact craters on our planet, but this is only the second time in history that a crater was discovered under an ice sheet. In November, NASA announced that it had discovered the first subglacial impact crater buried beneath the Hiawatha Glacier in Greenland, which is only 1
Inspired by this discovery, a team led by NASA glaciologist Joseph MacGregor began to search Greenland for other craters. The new crater seems to be bigger and older than the impact site of Hiawatha.
Both features were discovered using satellite imagery and aerial photography from NASA's IceBridge operation.
Because of their proximity to MacGregor and his colleagues. Considered whether these craters might have been formed by the same impact event. Maybe a binary asteroid system hit the Earth or an asteroid broke into two pieces as it entered the atmosphere.
However, the topography of the new crater shows that it is much more eroded than the Hiawatha crater, suggesting that they could not have formed simultaneously.
"The morphology of the second structure is flatter [and] is conformant and older," write MacGregor and his co-authors in the study. "We conclude that the identified structure is most likely an impact crater, but it is unlikely to be a twin of the Hiawatha impact crater."
The Hiawatha crater probably originated during the last 100,000 years. Further research is needed to limit the age of the second crater, but it is likely to date back to the Pleistocene epoch, which began 2,588,000 years ago. Based on the estimated age of its ice cover, it was formed at least 79,000 years ago, the team said.
The structure does not yet have an official name, but the authors recommended naming the Paterson Crater. This name would honor the late glaciologist Stan Paterson, who has contributed to the reconstruction of the climate data of the last 100,000 years with the help of ice cores from Greenland.
"The possibility of further subglacial craters among the Greenlandic and Antarctic ice sheets should be investigated, further underlining the ability of the ice sheets to both buried and preserve evidence of terrestrial impacts," the team said.
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