Effects of a Really-Near-Earth-Supernova?

December 28, 2005 9:36 AM

How close would a Near-Earth Supernova have to be to Earth to cause immediate surface effects? And what would those effects be?

Most of the articles I've read on the effects of a Near-Earth Supernova on Earth's biosphere deal with the elimination of the ozone layer and associated consequences - damage to the biosphere from solar radiation which now can reach the surface because of the lack of protection from the ozone layer. But they don't talk about immediate surface effects. I assume that if a supernova were to go off much closer to the Earth than the ozone-depeletion scenarios contemplate, that the radiation would overwhelm the atmospheric barriers and irradiate the surface immediately. Theoretically, how close would a supernova have to be to do this?

Secondly, what would the actual effects be, aside from a lethal dose of radiation to living things? What would it look like? Would the atmosphere fluoresce? Would fires ignite? What would a protected observer see happening on the Earth's surface?

posted by Chanther to science & nature (11 comments total)

Related.
posted by BorgLove at 9:45 AM on December 28, 2005

these might help (the last might be closest to what you want):
http://stupendous.rit.edu/richmond/answers/snrisks.txt
http://www.nagt.org/files/nagt/jge/abstracts/Dutch_v53n1.pdf
http://personals.galaxyinternet.net/tunga/SDPP.pdf
posted by andrew cooke at 9:48 AM on December 28, 2005

actually we are so close to our sun that it would eat us before exploding (i think suns get bigger when they're old.. like women ..and men)

i dunno whether the centauri suns (our closest neighbor suns but still far away) would have any effect on earth if they would go nova
posted by suni at 10:30 AM on December 28, 2005

oh, and i guess there would be the awesomest northern lights
posted by suni at 10:33 AM on December 28, 2005

If one of the centauri suns went, wouldn't we see the light from the beginnings of the explosion before the force of it reached us? Assuming it packs enough energy to cause us harm, wouldn't we have to sit here and helplessly watch our own doom coming toward us for a few years?

There's a neat science fiction and/or Christian armageddon story in there.

Seriously though, now I'm interested in the physics of this too. Perhaps some astronomy and astrophysics people can provide us with some useful facts to bring out at cocktail parties.
posted by aladfar at 12:53 PM on December 28, 2005

Well, that's right - we'd see radiation (Infrared, X-Ray, Gamma Ray) effects before ionized particles swept through the solar system. Heat (Infrared) and UV are photons though, so they would arrive at the same time as the visible light, and that might be enough to make our solar system an unpleasant place.
posted by Crosius at 1:13 PM on December 28, 2005

Interesting concept from the Bryson book A Brief History of Nearly Everything ... if the radiation from said supernova (or gamma ray burst) is moving at the speed of light, there would be absolutely no warning, since the light and radiation emitted immediately previous to the event is also moving at the speed of light.

In other words, you're looking at a completely normal, starry night sky and then ... zzzap.

shudder
posted by frogan at 2:00 PM on December 28, 2005

wouldn't we see the light from the beginnings of the explosion before the force of it reached us? Assuming it packs enough energy to cause us harm, wouldn't we have to sit here and helplessly watch our own doom coming toward us for a few years?

You beat me to the post ... but to reiterate the point ... you wouldn't see it coming, because everything is moving at the same speed.

You wouldn't see a "blast wave" coming, like you would with a normal explosion, because in a normal (chemical) explosion, the blast wave is moving slower than the light it emits. In this case, since everything is moving at the same speed, there's nothing to "see" before it gets here.
posted by frogan at 2:06 PM on December 28, 2005

there wouldn't be a just a zap, we would be able to see it while we get radiated/toasted
posted by suni at 6:30 PM on December 28, 2005

aladfar writes,There's a neat science fiction and/or Christian armageddon story in there.

I immediately thought of Aftermath when I saw this thread. It's a post-apocalyptic novel by Charles Sheffield.
posted by furvyn at 8:46 PM on December 28, 2005

Many thanks for the replies. I have a few leads now.
posted by Chanther at 6:55 AM on December 29, 2005