Gamma ray bursts are coming

A gamma ray burst could strike the Earth and destroy all life. The Earth has been struck in the distant past, which means that it's possible.

Gamma ray bursts can be seen in the sky on a constant basis. These bright flashes of light are a long way off (millions or billions of light years). They are the brightest emissions of electromagnetic energy in the universe, in many cases outshining the entire galaxy that they're in. Some even outshine the entire universe . . . for a split second.

Where do these massive blasts of energy come from? Many of these come from giant supernovae explosions of massive stars. They represent the most violent events in the universe; only second to the Big Bang itself. The reason why astronomers are concerned about these catastrophic events is the possibility that one could occur in our Milky Way galaxy, and if it's oriented so that it's pointed directly at Earth, it could end all life here. They estimate that one of these extinction events occurs every 5 million years. So, there have been about 1000 of them since the Earth began. Supposedly, the Ordovician-Silurian extinction (450 million years ago) may have been the result of one these gamma ray bursts. This event killed off the trilobites. I liked those trilobites, darn it!

A possible candidate for a gamma ray burst that could wipe out life on Earth is a Wolf-Rayet star 8000 light years away. If WR-104 were to supernova, it would be curtains for us because it would deplete 25% of the ozone layer, allowing too much lethal UV radiation to kill off food plants. People on the side of the planet facing the 10-second gamma ray burst would receive a fatal dose of radiation. The bad news is that there would be no advanced warning for this. In fact, it could have already happened. It just hasn't goten here yet because it takes 8000 years.

WR-104 is a binary star system. The primary star is a Wolf-Rayet star and its partner is OB star on the main sequence. Wolf-Rayet stars are massive O-type stars with a mass of 20 times that of our Sun. These stars have lost their hydrogen outer layers and are burning helium in their cores, which means that they are beyond the main sequence and ready to go supernova, and the problem is that the pole of the star is aimed like a gun directly at us.

Gamma ray bursts shoot out of the poles of the star when it goes supernova, and we are in the cross hairs of that potential extinction event.
Some astronomers conjecture that gamma ray bursts may be responsible for the so-called Fermi Paradox. This is where SETI (Search for Extraterrestrial Intelligence) has not detected a signal from an intelligent alien race. Gamma ray bursts may have killed them off.

Are we next?

The truth is that not all that much is known about these powerful blasts of energy. The theories about them are just that--theories. We have no real solid evidence for what a Wolf-Rayet star could do or when it could go supernova.

So don't worry, be happy!

Thanks for reading.