Greenland is covered with one of the largest ice sheets on the planet, but under its frozen exterior, the landscape is more pockmarked than ours.
Buried under two kilometers of ice, the researchers think they have found a second big impact crater, hiding in the northwest corner of the largest island in the world.
As scientists research more and more on our planet, it gradually sees new crater effects, especially in ice like Greenland or Antarctica.
In fact, before seeing the first impact effect on Hiawatha in November last year, most experts have assumed that any evidence of a previous effect was eradicated by erratic erosion regions.
So it's quite unusual that in just a few months, we have now discovered the look of two of these qualities, both located in Greenland.
"We have analyzed the Earth in many ways, from the ground, air and space ̵
The discovery was made possible by a combination of satellite images and radar data, allowing researchers to & # 39; see & # 39; under the ice.  They have already seen a circular pattern, just 183 kilometers (114 miles) from the first impact point. Measuring more than 36 kilometers wide (22 miles), the pattern is found to have similar features in its surrounding impact effect – specifically, a flat, shaped bowl of depression, surrounded by a raised rim and the peaks located in the middle.
While not clearly defined as the Hiawatha link, if the second impression confirmed the fingerprint of a meteorite, it would be the 22nd highest impression estimate found on Earth – three seats ahead of Hiawatha.
"The only other circular structure that can come up in this size is a collapsed volcanic caldera," explains MacGregor.
"But the areas of known volcanic activity in Greenland are several hundred miles away. Also, a volcano should have a clear positive magnetic anomaly, and we can not see it at all."
But although it appears that Hiawatha has a brother, it is likely that the two hooks are twins. The authors guess the second one is not just bigger, it's still older.
Case studies of ice cores were closely studied, MacGregor and his team determined that the area was not disturbed by a strong force for at least 79,000 years. This can mean two things: the effect has occurred over 79,000 years ago; or just recently happened and the crushed ice just came out.
However, guessing at an age crisis is difficult business. In this case, the researchers calculated that it was taken between one hundred thousand years and one hundred million years for ice to reduce the crater to its present shape.
"The ice layers above this second crater are older than the ones above Hiawatha, and the second wave is almost twice flexible," explains MacGregor.
"If the two were formed at the same time, the ice above the second crater would have equilibrated to the crater faster than Hiawatha."
It's also unusual, statistically, for two different meteorites so get very close to one & # 39; t one. Two sets of neighboring wedges are found in Ukraine and Canada, and computer models prove that these events are no longer heard in the Earth's crunch record .
"Having a third pair of irrelevant hooks is astonishing but we do not consider it to be likely," says MacGregor.
"As a matter of fact, the evidence we have developed indicates that the new structure is likely to be an effect of the effect, but it does not seem to now be a twin Hiawatha."
This study is published in Geophysical Research Letters .