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Since life has been on Earth and left a clear record with its fossils in the rocks, we can see that every sixty million years or so there have been widespread extinctions of life all round the Earth. One theory is that these are caused by huge meteorite impacts. These may be asteroids, comets or they may have come from outside the solar system. The energy they release is huge. It is far more than all our nuclear weapons exploding at the same time!
There was a mass extinction at around 250 million years ago. After that the dinosaurs began to dominate the Earth.
So if the sixty million year theory is correct we might be due for another impact any day now! Useful LinksClick for Further information about Mass Extinctions Other History of the Universe Pages News about History of the Universe |
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