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silylene old
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This is interesting !<br /><br /><b>Antarctic craters reveal strike</b><br /><br /> http://news.bbc.co.uk/1/hi/sci/tech/3580230.stm<br /> <br />The asteroid may have raised sea levels by up to 60cm <br />Scientists have mapped enormous impact craters hidden under the Antarctic ice sheet using satellite technology. <br />The craters may have either come from an asteroid between 5 and 11km across that broke up in the atmosphere, a swarm of comets or comet fragments. <br /><br />The space impacts created multiple craters over an area of 2,092km (1300 miles) by 3,862km (2,400 miles). <br /><br />The scientists told a conference this week that the impacts occurred roughly 780,000 years ago during an ice age. <br /><br />When the impacts hit, they would have melted through the ice and through the crust below. <br /><br />Professor Frans van der Hoeven, from Delft University in the Netherlands, told the International Geographical Union Congress in Glasgow that the biggest single strike seared a hole in the ice sheet roughly 322km (200 miles) by 322km. <br /><br />Impact melt <br /><br />This would have melted about 1% of the ice sheet, raising water levels worldwide by 60cm (2ft). <br /><br />The research suggests that an asteroid the size of the one blamed for killing off the dinosaurs 65 million years ago could have struck Earth relatively recently. <br /><br />Early humans would have been living in Africa and other parts of the Old World at the time of the strikes. <br /><br />But the impacts would have occurred during an ice age, so even tidal waves would have been weakened by the stabilising effect of icebergs on the ocean. <br /><br />The craters were resolved using satellite data to map gravity anomalies under the ice sheet. <br /> <br /> <div class="Discussion_UserSignature"> <div class="Discussion_UserSignature" align="center"><em><font color="#0000ff">- - - - - - - - - - - - - - - - - - - - - -</font></em> </div><div class="Discussion_UserSignature" align="center"><font color="#0000ff"><em>I really, really, really miss the "first unread post" function.</em></font> </div> </div>