Monday 3 June 2013

Unexpected FATE...

Around 450 million years ago, the Earth was devastated by a terrible disaster that annihilated around 85 per cent of all marine species – at the time, the predominant form of life on the planet.

Known as the Late Ordovician Extinction, it was the second most devastating blow to life on Earth during its history – worse even than the notorious impact-related event that forced the dinosaurs in the line of extinction 65 million years ago. Geological evidence points to a sudden plunge in global temperatures, though the cause remains uncertain. But one possibility is the explosion of a death star relatively very close to Earth.
Analysis of the effects of a gamma-ray burst by researchers at the University of Kansas and the US space agency NASA suggests it would have triggered the destruction of the Earth’s protective ozone layer, as it allowing intense ultraviolet radiation from the Sun to reach the surface. This would have wiped out many life-forms in the upper layers of the oceans – including plankton, a key part of the marine food chain.
It’s also possible that the changes in atmospheric chemistry triggered by the blast may, in turn, have it been triggered global cooling – though whether this would be enough to account for the Ordovician ice age is unclear.

What is certain is that the giant stars capable of producing gamma-ray bursts are spread throughout the cosmos. As such, it is not only life on Earth that’s threatened by them. According to research by known Professor James Annis of the Fermi National Accelerator Laboratory, Illinois, gamma-ray bursts may be then regularly sterilize their host galaxies; if that’s true, our chances of finding life elsewhere in the very Milky Way would be much reduced.

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