Washington, Dec 17 (): Supernova blast might occur less than 50 light-years away from earth in 2012. Astronomers are confident that it will not prove detrimental for life on earth, given the vastness of space and the long times between supernovae.
Here’s how Francis Reddy, from NASA’s Goddard Space Flight Centre, starts his article:
Given the incredible amounts of energy in a supernova explosion — as much as the sun creates during its entire lifetime — another erroneous doomsday theory is that such an explosion could happen in 2012 and harm life on Earth. However, given the vastness of space and the long times between supernovae, astronomers can say with certainty that there is no threatening star close enough to hurt Earth.
But the fact is that there are no stars near Earth that can go supernova and disrupt our planet, as Reddy explains right after that paragraph:
For Earth’s ozone layer to experience damage from a supernova, the blast must occur less than 50 light-years away. All of the nearby stars capable of going supernova are much farther than this.
Astronomers estimate that, on average, about one or two supernovae explode each century in our galaxy.
Another explosive event, called a gamma-ray burst (GRB), is often associated with supernovae. When a massive star collapses on itself or less frequently, when two compact neutron stars collide — the result is the birth of a black hole.
Any planet with life on it near a star that goes supernova would indeed experience problems. X- and gamma-ray radiation from the supernova could damage the ozone layer, which protects us from harmful ultraviolet light in the sun’s rays. The less ozone there is, the more UV light reaches the surface.
Astronomers estimate that a gamma-ray burst could affect Earth from up to 10,000 light-years away with each separated by about 15 million years, on average. So far, the closest burst on record, known as GRB 031203, was 1.3 billion light-years away.
As with impacts, our planet likely has already experienced such events over its long history, but there is no reason to expect a gamma-ray burst in our galaxy to occur in the near future, much less in December 2012.