Researchers from Louisiana State University, Stanford University and the U.S. Geological Survey report that an asteroid, estimated to be 12 to 30 miles wide, slammed into Earth nearly 3.5 billion years ago.

That asteroid was probably at least twice as wide as the meteor thought to have killed the dinosaurs 65 million years ago, and the impact probably released at least 10 times as much energy, the scientists said.

The heat would have killed all single-cell microbes, the only life on Earth at the time, on land and in the upper ocean, which would have boiled into steam. The impact appears to have sent giant tsunamis coursing around the world’s oceans, scouring the early continents.

”The only thing that would have survived would have been bacteria in the deep ocean,” said Dr. Gary R. Byerly, a professor of geology at Louisiana State and the lead author of the article.

Because of the scarcity of fossils from the era, scientists cannot say how the cataclysm changed the course of life.

Giant craters on the moon indicate to scientists that even earlier and larger impacts occurred on Earth. A heavy rain of meteors large enough to boil off the oceans would probably have delayed the advent of life until 3.9 billion years ago at the earliest, scientists say. But no rocks that preserve evidence of those early impacts have been found.

No crater from the crash 3.5 billion years ago remains either, but Dr. Byerly and Dr. Donald R. Lowe, a professor of geology at Stanford, found hints of the impact two decades ago: perfectly spherical sand grains about the size of BB pellets in ancient rocks from South Africa and western Australia. The grains probably condensed from the cloud of rock vapor sent up by the impact, the two scientists said.

Later research showed that the layers of rock containing the grains were also rich in iridium, a metal more abundant in asteroids and comets than in rocks on Earth. The layers of debris are 8 to 12 inches thick, compared with less than an inch for the impact that killed the dinosaurs.

Analysis of the minerals from the older impact indicated that the rock was an asteroid that had once orbited between Mars and Jupiter.

Scientists dated the impact by measuring the decay of uranium in zircon crystals in the rock. Zircon is a durable mineral formed from the force of the giant tsunamis crashing ashore.

The crystals in the both Australian and the South African rocks formed about 3.47 billion years ago, give or take a couple of million years, leading the scientists to conclude that they formed from the same impact.

1) Our meals and drinks are full of syrups, sugars and fats. 2) On this diet we for sure need medical help. 3) Pills work both ways and we are “healthy” as per definition in the books. 4) But just a little tweaking… 5) and to sugarcoat it all – over 2 weeks of vacation is too much for any solid employment path!

Think about the huge savings to our struggling SS Trust Fund when the Baby Boomers and their children will “expire a little early” and they don’t even know this. Unfortunately, talk of derailing the current “Health” train makes the Congress to feel threatened and unsecure!

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