Betelgeuse, Betelgeuse, oh crap!

Sooooo.... not upset you.... but it's possible that the star Betelgeuse may have blown up.

The red giant star Betelgeuse in the constellation Orion is shrinking rapidly. And when I say 'rapidly' I mean - astronomically fast. Astronomers say that it has shrunk by 15 per cent since 1993, by which they mean that it actually did so in the mid 16th century. The speculation is that, in fact, it already exploded.

Betelgeuse, before it shrank, was thought by astro boffins to be so large that if it were placed in the middle of our solar system, Jupiter - out beyond the asteroid belt in reality - would lie inside it. Now it has shrunk by a distance equal to the orbital radius of Venus. That's some major shrinkage.

"To see this change is very striking," said Charles Townes, UC Berkeley emeritus physics prof and Nobel Prize winner. "We will be watching it carefully over the next few years to see if it will keep contracting or will go back up in size."

The huge star, one of the brightest in the sky, is thought to lie about 430 light years from our solar system, so the changes being observed now actually occurred in 1579 AD. Many boffins believe that Betelgeuse is so vast that it's liable to go supernova - that is, blow up with stupendous, galaxy-shaking force - within a millennium or so. Indeed, it might already have exploded at some point in the last 430 years, in which case the flash wouldn't yet have reached us.

"We do not know why the star is shrinking," says Edward Wishnow of US Berkeley's space sciences lab. "Considering all that we know about galaxies and the distant universe, there are still lots of things we don't know about stars, including what happens as red giants near the ends of their lives."

To you supernerds out there, you'll remember that Betelgeuse - specifically the notional planet Betelgeuse V - was said to be the home world of two-headed, three-armed renegade Galactic President Zaphod Beeblebrox and his childhood friend and 'semi-cousin' Ford Prefect, in the Hitchhiker's Guide to the Galaxy by Douglas Adams.

What's amazing is that when we do see that sucker go Supernova, it's going to light up the night as clear as day. Apparently a supernova explosion at such a short distance is capable of wreaking such havoc on Earth that climate change would be the least of our problems. The main culprit would be the gamma-ray blast.

That, some speculate, will happen in 2012. The same year the Myan calender ends. Whoa.