Wednesday, April 25, 2012

Late heavy bombardment update

New research reveals that the Archean era -- a formative time for early life from 3.8 billion years ago to 2.5 billion years ago -- experienced far more major asteroid impacts than had been previously thought, with a few impacts perhaps even rivaling those that produced the largest craters on the Moon, according to a paper recently published online in Nature.

They found that approximately 70 (and 4) dinosaur killer-sized or larger impacts hit the Earth (and Moon) over a span that lasted between 3.8 and 1.8 billion years ago.

The implication of such enormous impacts over the Archean era is unknown, but some are believed to have released nearly 500 times the blast energy of the Chicxulub impact. (aka the one that wiped out the dinosaurs)

"It will be interesting to see whether these mammoth events affected the evolution of early life on our planet or our biosphere in important ways," says Bottke. 

Quotes are from the ScienceDaily report and the original paper is here:
An Archaean heavy bombardment from a destabilized extension of the asteroid belt. Nature, 2012

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