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Let’s go check it out.
I wish they would stop presenting wild guesses as fact.
interesting, but at the moment I am quietly contemplating the metaphysical properties of a boal of Corn Flakes.
Gyr? I’m assuming that means billions of years, but I’ve never seen it stated that way before (B4).
Scientists Confirm Age Of The Oldest Meteorite Collision On Earth...Scientists have yet to locate any trace of the extraterrestrial object itself or the gigantic crater it produced, but other geological evidence collected on two continents suggests that the meteorite was approximately 12 miles (20 kilometers) wide -- roughly twice as big as the one that contributed to the demise of the dinosaurs some 65 million years ago... To pinpoint when the huge meteorite collided with Earth, Lowe and his colleagues performed highly sensitive geochemical analyses of rock samples collected from two ancient formations well known to geologists: South Africa's Barberton greenstone belt and Australia's Pilbara block... Although thousands of miles apart, both sites contain 3.5-billion-year-old layers of rock embedded with "spherules" -- tiny spherical particles that are a frequent byproduct of meteorite collisions... The meteorite that led to the dinosaur extinction produced spherule deposits around the world that are less than 2 centimeters deep. But the spherule beds in South Africa and Australia are much bigger -- some 20 to 30 centimeters thick. A chemical analysis of the rocks also has revealed high concentrations of rare metals such as iridium -- rare in terrestrial rocks but common in meteorites... isotopic studies confirmed that much of the chromium buried in the rock samples came from an extraterrestrial source... In addition to the 3.47-billion-year-old impact, Lowe and Byerly have found evidence of meteorite collisions in three younger rock layers in the South African formation. According to Lowe, the force of those collisions may have been powerful enough to cause the cracks -- or tectonic plates -- that riddle the Earth's crust today.
Science Daily
Stanford University
8/23/2002
Yeah, right.Meteor bombardment 4 bln yrs ago may have made Earth more habitableWhen a meteorite enters a planet's atmosphere, extreme heat causes some of the minerals and organic matter on its outer crust to be released as water and carbon dioxide (CO2) before it breaks up and hits the ground.
ANI
June 2nd, 2009
Researchers suggest the delivery of this water could have made Earth's and Mars' atmospheres wetter.
The release of the greenhouse gas CO2 could have trapped more energy from sunlight to make Earth and Mars warm enough to sustain liquid oceans.
Physics News Update Number 262IN THE LATE HEAVY BOMBARDMENT (LHB) EPOCH , a span of about 200 million years some 4 billion years ago, the Moon sustained many large impacts. Some astronomers believe that the projectiles responsible may have pestered Mercury, Venus, Earth, and Mars as well. Others assert that the LHB phenomenon was unique to the Earth-Moon system or that it did not happen at all, at least not so suddenly. Now, a group of scientists at the University of Manchester (UK) has dated a rock found here on Earth but which is believed to have been a meteorite originating at Mars. The 4-billion-year age of the object, determined by isotope dating, is much older than previously studied Martian meteorites. The antiquity of the rock, say the researchers, provides evidence for a widespread LHB effect. (R.D. Ash et al, Nature, 7 March 1996.)
by Phillip F. Schewe and Ben Stein
March 14, 1996
Asteroids Resurfaced The Earth and Inner Solar System 3.9 Billion Years AgoThe bombardment that resurfaced the Earth 3.9 billion years ago was produced by asteroids, not comets, according to David Kring of the University of Arizona Lunar & Planetary Laboratory and Barbara Cohen, formerly at the UA and now with the University of Hawaii... The significance of this conclusion is that the bombardment was so severe that it destroyed older rocks on Earth... the reason why the oldest rocks found are less than 3.9 billion years old... This same bombardment according to Kring and Cohen, affected the entire inner solar system, producing thousands of impact craters on Mercury, Venus, the Moon and Mars. Most of the craters in the southern hemisphere of Mars were produced during this event. On Earth, at least 22,000 impact craters with diameters greater than 20 kilometers were produced, including about 40 impact basins with diameters of about 1,000 kilometers in diameter.
by Julieta Gonzalez
28-Feb-02
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Gods |
Thanks decimon. Pinging GGG a bit later. :') |
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When are we due for our next *resurfacing*?
That’s what I’ve been saying all along.......and people just laughed at me.