Tuesday, August 17, 2004

A plethora of disasters

Just when you thought it was safe to come out of the movie theater, geologist Bill McGuire reminds us again of the chunk of the Azores that is about to fall into the sea, causing a giant tidal wave that would wipe out US coastal cities.

Well, here's some good news.

One of the most violent threats in the universe is having a nearby star go supernova.

If a star as close as 50 light-years exploded, the blast would sweep the Earth with a burst of deadly gamma rays, x-rays, and a straggling wave of high energy cosmic rays moving at nearly the speed of light. Life on Earth would suffer a terrible blow.

Within 50 light-years of the Earth there are approximately a thousand stars. The vast majority are smaller and less luminous than the Sun, and according to present theories small stars are unlikely to die with a bang.

If you insist on worrying about supernovas, keep your eye on the familiar star Rigel in the constellation Orion. It is a hot supergiant at that stage in its life when the balance of gravity and energy production can go dangerously askew.

If Rigel goes supernova, it will become as bright as the moon. It will be the most spectacular celestial event in recorded human history, but -- because of its distance, 900 light-years -- relatively benign.

There, now don't say I didn't cheer you up.