Supernova threatens Earth

OK, not really.

But what if it did? Is it really that outlandish a thought?

Climate change probably shouldn't be a political topic, but, alas, it is. So I'm indulging my love of science and talking about it.

Climate change is also a subject of lively debate among archaeologists and paleontologists -- could it have been climate change that killed off the dinosaurs, or was it a meteorite striking Earth? Could animals like the woolly mammoth have been offed by advancements in hunting tools made by our primitive ancestors, or could it have been global warming or cooling?

Maybe it was neither, suggests blogger Gregg Easterbrook, who, admittedly, is not quite a scientist. He is a football blogger for ESPN, editor at the New Republic magazine, a Brookings Institution fellow and global warming skeptic-turned-alarmed-believer.

In a blog entry last week, Easterbrook talked about GRB 060218, a supernova recorded in February by Swift, a cool NASA satellite designed to look for the very gamma-ray bursts a supernova generates.

GRB 060218 is 470 million light years away, which means this massive star explosion happened 470 million years ago.

Easterbrook wonders what would happen if a supernova this gigantic -- this was truly a big one, even compared with other supernovae -- were to detonate in the Milky Way.

Given the amount of gamma-ray radiation emanating from such a blast, Easterbrook guesses such a stellar death in this galaxy would extirpate all life on Earth. The planet would be sterilized.

It's happened before -- gamma-ray bursts in far-away galaxies have affected Earth twice in the last 350,000 years -- and Easterbrook suggests massive die-offs might have been the result.

So should politicians be worried about defending Earth against supernovas? Maybe not, but keeping research and development dollars in NASA projects, both terrestrial and celestial, is a good idea.

Then, at the very least, we can keep learning about such cool things.