Replies to This Discussion

Permalink Reply by Boothby171 on January 10, 2010 at 8:32pm

Cataclysmic solar flare (or solar storm)?
http://dsc.discovery.com/videos/perfect-disaster-solar-storm.html
http://dsc.discovery.com/space/my-take/solar-storm-sten-odenwald.html

" For example, we know that the worst times for solar storms are during solar maximum. The next one will happen between 2011 and 2012 because it follows a cycle we have mapped out for the last 150 years."

Permalink Reply by The Secular One on January 10, 2010 at 9:28pm

Neutron star fragments passing through the solar system, shooting out beams of deadly radiation at more or less random as they pass the Earth, killing everything in the spot where they strike.

Permalink Reply by The Secular One on January 11, 2010 at 5:59am

A slightly more realistic cosmic event would be a nearby supernova.

Permalink Reply by Wonderist on January 10, 2010 at 10:58pm

You could go for something environment related. Like massive algae dieoff causing subsequent worldwide ecosystem collapses, food shortage, subsequent wars, etc. Or a sudden shift in weather patterns with much the same effect. Consider if it started to rain too much where it's usually dry, and become dry where it's usually rainy. Crops that have evolved for rainy areas, like rice, would dry up, and crops for dry areas would become over flooded. If it was a sudden change, there would not be enough time to adapt. All you really need is some serious food or water shortages to cause famine. And any time you have that kind of upheaval, there's bound to be war to add even more deaths. It is suspected that when Antarctica separated from South America, the resulting change in oceanic currents caused massive global weather changes.

If you want something truly cosmic, there are only two sources which are really credible. Big impact meteors, and the Sun. There's a good book, Lucifer's Hammer, by Niven and Pournelle about a meteor that breaks up into multiple pieces and impacts like a shotgun blast across the entire planet. The meteor Shoemaker-Levy had a similar impact into Jupiter a few years back. By breaking it up, you get many small impacts instead of one ginormous one. The latter would likely lead to major extinctions. The former would spread the damage around and would potentially be survivable. You'd have to make it less extensive than the Lucifer's Hammer one, though, because that one pretty much ended civilization, not just massive dieoffs.

The other option is the Sun. Unfortunately, I don't think it's very realistic. It would have to be something totally unknown to us, or something exceedingly rare. Still, it's a massive fusion reactor just 8 light-minutes from Earth. That's a lot of power. No evidence of massive dieoffs in the past from solar events, though.

Oh, you could also have a massive super-volcano eruptions spewing CO2, carbon monoxide, sulphur dioxide, etc. Several major extinctions in the past are suspected of being caused by super-volcanoes. Again, it would be tough to have it big enough to cause massive die-offs, but small enough not to cause total extinction or the end of civilization.

A non-cosmic, but still sorta cosmic, event could be a back-firing technological singularity, where some AI or transhuman or something goes haywire and winds up thinking it's god or something and wipes out most of humanity before finally offing itself. Think of what a suicide bomber with a brain the size of a planet could do.