'Death Star' Aimed at Earth

An anonymous reader writes "A spectacular, rotating binary star system is a ticking time bomb, ready to throw out a searing beam of high-energy gamma rays that could lead to a major extinction event — and Earth may be right in the line of fire. Australian science magazine Cosmos Magazine reports: 'Though the risk may be remote, there is evidence that gamma ray bursts have swept over the planet at various points in Earth's history with a devastating effect on life. A 2005 study showed that a gamma-ray burst originating within 6,500 light years of Earth could be enough to strip away the ozone layer and cause a mass extinction. Researchers led by Adrian Melott at the University of Kansas in Lawrence, U.S., suggest that such an event may have been responsible for a mass extinction 443 million years ago, in the late Ordovician period, which wiped out 60 per cent of life and cooled the planet.'"

Comments

Thanks guys

[NIckGorton]

Further research would be required to determine if we are exactly in line with the axis of the system - but even if we are, we probably still have hundreds of thousands of years to come up with a solution, said Tuthill. Thanks for putting that at the end of TFA. Now I need to go change my shorts.

The Bad Astronomer has covered this on his blog.

[jdoss]

Right here.

Re:Atmosphere? What atmosphere?

[SatanicPuppy]

Nah, polarity flips have been happening for a long time; if we lost our atmosphere every time, this planet would LOOK like mars...Anyway, Mars has no atmosphere because it's too small, not because it doesn't have a liquid core with the attendant magnetic field. Losing the magnetic field (which may or may not happen during a flip...Geologic data isn't precise enough to tell) could cause some problems with regards to the solar wind, but complete loss of atmosphere is extremely unlikely.

The average period between pole flips is about 250,000 years, so that will give you a pretty good idea of how often it happens, and how unlikely it is that atmospheric loss follows. For the curious, it's been about 800,000 years since the last flip, so we're due one.