i feel another bad SciFi channel movie coming on...

today in BBC news: gamma radiation does not turn us into the hulk.

BBC News, 11 April 2005: Ray Burst is Extinction Suspect

A gamma ray burst could have caused the Ordovician extinction, killing 60% of marine invertebrates at a time when life was largely confined to the sea.

These cosmic blasts are the most powerful explosions in the Universe.

The scientists think a 10-second burst near Earth could deplete up to half of the planet's ozone layer.

With the ozone layer devastated, the Sun's ultraviolet radiation could have killed off much of the life on land and near the surface of oceans and lakes.

Gamma ray bursts are rare occurrences, but scientists estimate that at least one must have occurred near the Earth in the past one billion years.

[snip]

"A gamma ray burst originating within 6,000 light-years from Earth would have a devastating effect on life," said co-author Dr Adrian Melott, an astronomer at the University of Kansas, US.

"We don't know exactly when one came, but we're rather sure it did come - and left its mark. What's most surprising is that just a 10-second burst can cause years of devastating ozone damage."

Surface-dwellers

Dr Melott and his colleagues used computer models to calculate the effects of a nearby gamma ray burst on the Earth's atmosphere and its life forms.

They showed that up to half the ozone layer would be destroyed within weeks. Five years on, at least 10% would still be missing.

Although deep sea creatures would be protected from the effects of the burst, surface-dwelling plankton and other life near the top of the ocean would not survive.

This would have had huge implications for other life forms, because plankton form the foundation of the marine food chain; they provide for animals which are then eaten by larger species.

[snip]

The latest research shows that a gamma ray burst could have caused a fast die out early on and could also have triggered a drop in temperature similar to the effect of an ice age.

Swift, a Nasa space mission launched in November 2004, is currently investigating the phenomenon of gamma ray bursts from Earth orbit.

well, it's that last line that makes me feel so secure. yeek.

that and the bit about the loss of ozone killing off almost all life on the planet back to the unicellular range.