Scientists have uncovered a huge 31-kilometre-wide crater deep below the ice sheets in northwest Greenland. The crater was formed as a result of the impact of an iron meteorite less than three million years ago. Notwithstanding the impact, it is currently in well-preserved condition, according to NASA.
It is the first time that an impact crater of any size has been found underneath the continental ice sheets on Earth.
The crater was first noticed by a team of Danish researchers in 2015 while studying a topography map of the area beneath Greenland's ice sheet. In the map, researchers identified a circular depression under the Hiawatha Glacier and suspected that it could be an impact crater.
The team then investigated NASA data in detail to confirm their suspicion. They analysed images captured by the Moderate Resolution Imaging Spectroradiometer instrument on NASA's Terra and Aqua satellites.
In 2016, a research plane flew over the Hiawatha Glacier to map the area and the ice above it. The findings also confirmed the presence of a huge crater in that specific area.
"NASA makes the data it collects freely available to scientists and the public all around the world," said Joe MacGregor, a NASA glaciologist at Goddard Space Flight Centre in Greenbelt, Maryland, who was involved in the study in its early stages.
"That set the stage for our Danish colleagues' 'Eureka' moment."
According to NASA, the crater is about 300 meters deep and 31 kilometers wide. It is one of the 25 largest impact craters on Earth. The meteorite that caused formation of the crater was about 800 meter wide and penetrated about seven kilometres into the Earth's crust. The crater was later covered in the ice, and remained hidden from the view until it was first noticed in 2015.
The study was led by researchers from the University of Copenhagen and the Centre for GeoGenetics at the Natural History Museum of Denmark.
According to research team, the crater is in perfect condition and did not experience any erosion due to the glacial ice.
The team now plans to investigate the impact of meteorite event on the planet as a whole.
The findings of the study are published in the journal Science Advances.
All images by, and copyright of, NASA
J1043+2408 was observed for more than 10 years, and its radio light curve exhibited a periodic signal repeating in about 563 days
Success of Unity's test flight means Virgin Galactic is now close to taking its first paying tourist into space
V3 puts the pro-level football GPS tracker through its paces, and asks if it's more than a gimmick
Finding refutes many earlier studies that suggest that galaxies don't have much dark matter at the time of their birth