A long time ago, a giant space rock
slammed into what is now Greenland.
If you’re wondering why you haven’t heard
of this massive meteorite crash,
that’s because for millennia,
evidence of the impact was hidden
beneath the ice of Hiawatha Glacier
in Northwest Greenland.
Until now.
Recently, aerial radar surveys revealed
a depression under 930 meters of ice.
And now an image of the meteorite impact
has taken shape.
At 31 kilometers across and about 320 meters deep,
the hole rivals the size of cities like
Washington, D.C., and Paris.
Researchers put it among the 25 largest
impact craters on Earth.
The space rock was probably a rare iron asteroid.
To leave such a dent in Earth’s crust,
it had to be roughly 1.5 kilometers wide.
And when the asteroid hit,
it vaporized up to 20 cubic kilometers of rock.
That’s enough rock to fill 15,000 Astrodomes.
Other signs of the fiery fallout persist in the landscape.
Quartz crystals in sediment from a nearby river
showed deformities typical of a space rock collision.
The impact sent molten bits of rock
from Earth into the air.
And glassy grains in the same sediment
may even be some of that flash-melted debris.
The big question is, exactly how old is the crater?
It’s probably no older than the ice sheet.
That formed at the beginning of the Pleistocene.
So the crater is probably somewhere between
2.6 million and 11,700 years old.
But only further studies can confirm
and narrow that range.
A lot rides on the age of the crater.
There’s fierce debate
over something called the Younger Dryas.
That’s the technical name for a chilly period
that began about 12,800 years ago.
But we don’t know exactly
what triggered the deep freeze.
If the age of the Hiawatha crater matches up,
it could bolster a controversial hypothesis
that a space rock caused the 1,000-year cold snap.
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