Scientists have discovered what could be a 22-mile impact crater buried deep beneath Greenland's ice.
If so, this would be the second discovery announced in recent months.
A NASA glaciologist detects signs of a potential crater in northwest Greenland, just 114 miles from the recently discovered crater below Hiawatha Glacier, while scanning satellite imagery and topographic maps of the area.
How and when it has formed is still a mystery, though researchers still guess a riddle. It may be more than 80,000 years old.
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A NASA glaciologist discovered signs of a potential crater in northwest Greenland, just 114 miles from the recently discovered crater below the Hiawatha Glacier (pictured) Thinning Satellite Images and Topographic Maps of the Region
The researcher analyzed images from NASA's Terra and Aqua satellites along with NASA's IceBridge and discovered a seemingly bowl-shaped depression in the bedrock. The suspected crater is estimated to be 22.7 miles wide (shown)
"We have surveyed the Earth in various ways from land, air and space – it is exciting that such discoveries are still possible," said Joe MacGregor, a glaciologist at NASA's Goddard Space Flight Center, who helped discover a crater announced in November 2018.
This crater, estimated to be 30 kilometers wide, is located below the Hiawatha Glacier and is now the first impact crater ever to be found beneath the earth's ice sheets.
It used to be believed that most of the evidence of ancient impacts was erased by erosion of the overlying ice over many years.
After the first discovery, however, the team began to suspect there may be others.
"I began to wonder," Is this another impact crater? Do the underlying data support this idea? "MacGregor said.
"The identification of a large impact crater under the ice was already very exciting, but now it looks like two of them might exist."
The researcher analyzed images of the devices with moderate imaging resolution Spectroradiometers on NASA's Terra and Aqua satellites and NASA's IceBridge discovery discovered a bowl-shaped depression in the subsurface.
The suspected crater is estimated to be 22.7 miles (22.7 miles) wide.
According to the team, it would be the 22nd largest impact crater in the world if it turns out to be real.
"The only other circular structure that could approach this size would be a collapsed volcanic caldera," MacGregor said.
"But the areas of known volcanic activity in Greenland are several hundred kilometers away. In addition, a volcano should have a clearly positive magnetic anomaly, and we do not see that at all. "
Although the new crater is located only 114 miles away from the one announced in November, the researchers do not seem to be educated at the same time.
Scientists have discovered what could be a 22-mile impact crater buried deep beneath Greenland's ice
The ice in the area is at least 79,000 years old, says the team.
If this really is an impact crater, the researchers say it happened either more than 79,000 years ago or, more recently, all the ice has eroded from time.
"The ice sheets over this second crater are clearly older than those over Hiawatha, and the second crater is about twice as eroded," MacGregor said.
"If the two formed at the same time, the probably thicker ice over the second crater would have been compared to the crater much faster than for Hiawatha."
The team says it's possible that the two adjacent craters were simply formed by completely separate impact events.
WHAT WAS THE IMPACT CRATER FOUND BY HIAWATHA IN NOV 2018?
An impact crater left by the event 30 kilometers wide (30 km) remained hidden under the island for at least 12,000 years Hiawatha Glacier in remote Northwest Greenland
Scientists have recently identified the alleged first impact crater found beneath one of the Earth's ice sheets. The gigantic meteor crater, which was five times the size of Paris, was found half a mile below the ice in Greenland.
It is one of the largest impact craters in the world, pointing to a width of 300 meters (1,000 meters) of iron that hit our planet during the last ice age.
It is believed that the resulting explosion threw hundreds of miles in each direction, reaching as far as present-day Canada.
The 12 billion-meteor meteor landed with the power of 47 million Hiroshima bombs and destroyed all life within a 100-km radius, scientists said.
The crater measures 31 miles (31 miles) in diameter, five times the size of Paris. The scientists studied the size and shape of the crater to predict the potential impact of the meteor.
An impact crater (30 km) left by the event was hidden beneath the Hiawatha Glacier for at least 12,000 years in remote northwestern Greenland, although scientists have not categorized the event categorically.
It could have been three million years ago, when the Greenland ice sheet had already formed.
The crater was identified from the data collected between 1997 and 2014, supplemented by additional data collected in 2016 using an advanced form of radar noise.
This is consistent with the Earth's crater record, they say.
"This does not exclude that It is possible that the two new Greenland craters were made in a single event, such as the effects of a well-separated binary asteroid, but we can not argue for that," William Bottke said , a planetary scientist at the Southwest Research Institute in Boulder, Colorado.
"The existence of a third pair of unrelated craters is modestly surprising, but we do not consider it unlikely," said MacGregor.
"All in all, the evidence we have gathered shows that this is new. The structure is most likely an impact crater, but at present it seems unlikely that it is a twin with Hiawatha."