Sea Life Wiped Out by Neutron Star Collision?

Memorize writes "Scientists report in the Journal of Astrophysical Letters that a mass extinction of marine life 450 million years ago might have been caused by radiation from an exploding star, such as a collision between two neutron stars, or a neutron star collapsing into a black hole. Such an event would cause a ten-second burst of gamma radiation, and if it occurred within our galaxy, it could have wiped out many species on earth. At least if astronomers find out that an asteroid is heading our way, we can do something about it, but if there is a gamma burst, we get no warning. And if we did, would there be any way to protect the planet?"

Comments

Re:Scary Stuff

[Astro Dr Dave]

Gamma ray bursts are an area of active research; we now believe that they emit radiation along some polar axis, rather than isotropically in every direction. That probably accounts for the difference in distances you've seen quoted; for some fixed power level, an anisotropic GRB is dangerous from a greater distance if you happen to lie in the beam.

it's the ozone layer, not the radiation

[cahiha]

Given a number of confused responses to this, let's just remind everybody: it's not the gamma rays that kill (they would only get half of the globe anyway), it's the stripping away of the ozone layer followed by intense UV radiation. That's why it's a global effect.

While that would cause huge famines and disease and kill almost all humans, it is something that our species could survive given our technology.

Loss of ozone

[erice]

Any gamma burst from a single point will only fall on half the Earth's surface directly. What stops us from just hopping across to the other half, instead of needing scifi tech to survive?

Short Answer: RTFA
Long Answer:

The Gamma rays would destroy the ozone on the unlucky side. Once the ozone redistbutes, you are down to 50% everywhere. That is, aparently, enough to kill plankton. Probably would kill land plants, too.

So, on the unlucky side everybody dies. On the lucky side, crops fail for several years. Very bad news, though I doubt it would actually exterminate the human race. Plants would still grow in UV filtered green houses.