next »

[Dugdog47]

 : By Douglas Main, OurAmazingPlanet Staff
Writer
Published: 06/29/2012 03:29 PM EDT on
OurAmazingPlanet

A study of Greenland's rocks may have
turned up something unexpected: the
oldest and largest meteorite crater ever
found on Earth.

Researchers think the crater was formed 3
billion years ago, making it the oldest ever
found, said Danish researcher Adam Garde.
The impact crater currently measures about
62 miles (100 kilometers) from one side to
another. But before it eroded, it was likely
more than 310 miles (500 km) wide, which
would make it the biggest on Earth, Garde
told OurAmazingPlanet.

The team has calculated it was caused by a
meteorite 19 miles (30 km) wide, which, if it
hit Earth today, would wipe out all higher
life.

 Mystery feature

In the 3 billion years since impact, the land
has been eroded down to about 16 miles
(25 km) below the original surface. But the
effects of the intense shock wave and heat
penetrated deep into the Earth, and remain
visible today, said Garde, a researcher at
the Geological Survey of Denmark and
Greenland. [Meteor Mania: How Well Do
You Know 'Shooting Stars'?]

Garde had been conducting research on
Greenland's geology and noticed several
strange features that didn't make sense.
One day in September 2009, he came up
with the extreme explanation of an impact
from a meteorite. His team collected
samples over the years and published the
results in the July issue of the journal Earth
and Planetary Science Letters. He's now
"100 percent positive" it's a crater, for
several reasons, he said.
 
http://www.huffingtonpost.com/2012/06/29/meteorite-crater-greenland-oldest-biggest_n_1638841.html

[KB723]

That was pretty cool, but I am curious how something erodes to be smaller....

[Dugdog47]

Hmm....good question.

[KB723]

Hmm....good question.

I found that to be quite Curious... 

[wyley_wombat]

That was pretty cool, but I am curious how something erodes to be smaller....

Greenland has had it's surface scraped by glaciation for thousands of years.  It had to be pretty damn big or there would be no trace of it. 

[KB723]

Greenland has had it's surface scraped by glaciation for thousands of years.  It had to be pretty damn big or there would be no trace of it.

Thanks wyley, that does make sense, was it mentioned in the article, cos if it was I missed it...

[wyley_wombat]

All the article said was "destroyed by erosion and the like"  and no it did not mention glaciation.

[KB723]

All the article said was "destroyed by erosion and the like"  and no it did not mention glaciation.

I read it early and was still enjoying my first cup of coffee. Thanks, I wasn't really sure... How did you come up with that, have you worked in the field? 

[wyley_wombat]

have you worked in the field?

No I have not, I am just an audio/ video electronics geek by profession and an amateur astronomer.   BUT  I read a lot of articles on biology, geology, and paleontology.  Politics is only my number 2 interest; the sciences are at the top of the list.

[KB723]

No I have not, I am just an audio/ video electronics geek by profession and an amateur astronomer.   BUT  I read a lot of articles on biology, geology, and paleontology.  Politics is only my number 2 interest; the sciences are at the top of the list.

Coool as Hell, it always helps to have someone with such knowledge on board... 

[Tags:]