Eta Carinae – A Risk to Earth?
According to a recent report, it could affect Earth when it goes supernova, but not in a way you’d think…
The Good News (according to current models)
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Fortunately, Eta Carinae is far away, at least 7,500 light-years from Earth. If it explodes, most of its energy will be scattered or absorbed in the vast emptiness of space. It also happens to be tilted about 45 degrees from the line of sight to Earth, so any type of gamma-ray burst, a high-energy outburst expected with this star’s eventual eruption, would miss the Earth. Cosmic rays would be diffused by magnetic fields, and most of the damaging light would not affect life on Earth.
The Potentially Bad News
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But what if a supernova were 100 times brighter than usual? Would there be any risk to life on Earth then? Astronomers found such a record-breaking supernova last year, SN 2006gy.
It turns out that even though SN 2006gy was one of the brightest supernovae ever recorded, it did not generate a large amount of X-rays. Thomas and his team found most of the light, including damaging X-rays and cosmic rays, would scatter into space before ever reaching Earth.
So would there be any damage to Earth from such a spectacular event? Though Thomas found X-rays and cosmic rays would cause little damage, he also looked at optical light, particularly short-wavelength blue light (400 nanometers), where the spectrum of SN 2006gy peaked. No one had ever considered the effects of this light before, either from supernovae or any other type of event.
…In a paper about to be published in the journal Astrobiology, Thomas explains that even short exposures to blue light can increase insomnia, reduce resistance to infection and is being studied as a possible risk of cancer.
Yet, in the case of Eta Carinae, the effect of these optical photons would be minimal. The scattering of photons by dust and gas is greatest at blue wavelengths (thus giving Earth its blue sky) and the sheer distance of Eta Carinae diminishes the optical intensity by about 20 percent.
Of course, there’s nothing stopping Eta Carinae being 100x brighter than any previous supernova. But because such a supernova hasn’t been witnessed yet, orthodox science won’t accept it as a possibility.
