Aside from the Big Bang, the most powerful explosions in the universe are Gamma Ray Bursts. They send out beams of gamma rays that can be seen billions of light years away.

Scientists at the University of Kansas believe that one of these bursts was responsible for a great mass extinction on Earth, 450 million years ago in the Ordovician Period. If it should ever happen again, the explosion itself would not be felt on Earth, but the gamma radiation would wreak havoc in our atmosphere. Humanity would be in big trouble.

Gamma Ray Bursts were totally unknown before the late 1960s, when they were accidentally discovered by spy satellites keeping tabs on the Soviets for violations of the Nuclear Test Ban treaty. They were a huge mystery and remained so for nearly 30 years, when newer, better satellites showed these events to be enormous, as well as extremely far away. A Gamma Ray Burst of a few seconds or minutes puts out as much energy as 1,000 stars such as the sun do in their entire life spans.

In the 1990s, pieces of the puzzle began to fall into place. Evidence showed Gamma Ray Bursts occurred in two types, long and short. Most of what is known thus far is based on clues from long bursts, which last from two to a hundred seconds. The long bursts are caused by super massive stars collapsing into black holes. Short bursts, which last for less than two seconds, may have an entirely different cause. It is believed they form during the crashing merger of two neutron stars. This could be important for us, since these neutron stars are much more common in our own galaxy than super massive stars. Astronomers today continue to chase down the true nature of these beasts.

Our hypothetical Mega Disaster involves one of these two events occurring, about 6,500 light-years from Earth or closer. Like the Ordovician Mass Extinction, the gamma rays would strip away the ozone layer and generate a chemical smog, producing a widespread chill that would grip the Earth. It would be a massive one-two punch that would collapse food chains and result in a prolonged worldwide famine. In addition, all of our electronic systems would be disabled by the anticipated electromagnetic pulse. Scientists predict the Earth would be able to support only five to ten per cent of its current population, meaning that close to six billion people would die, most by starvation.

Among those interviewed are scientists from the University of Kansas, who calculated the effects of a Gamma Ray Burst on Earth, as well as the astronomers running the SWIFT satellite program, which is the key element in Gamma Ray Burst science today. The show is filled with beautiful NASA animations illustrating Gamma Ray Bursts as well as our own state-of-the-art 3-D animations, depicting events like the massive flash appearing in our sky which would blind anyone looking up, and a Los Angeles frozen under the new suddenly-cold climate.