Top 5 Ways the Universe Could Wipe Out Humankind

The Universe looks like a pretty tranquil place to live, doesn't it? During the day the sun shines steadily, and at night the heavens are reassuring and unchanging.

Dream on. The Universe is filled to the brim with dangerous, nasty things, all jostling for position to be the one to wipe us off the face of the planet. Happily for us, they're all pretty unlikely—how many people do you know who have died by proton disintegration?—but if you wait long enough, one of them is bound to get us.

But which one?

Death by Asteroid

(Photo by Stocktrek Images/Getty Images)

Of all the ways we might meet our untimely demise, getting wiped out by an asteroid is the most likely. Why? Because we sit in a cosmic shooting gallery, with 100 tons of material hitting us every day. The problem, though, occurs every few centuries when something big this way comes. If you could ask a dinosaur, I'd imagine they'd tell you to take this seriously.

And we do. The B612 Foundation is a collection of scientists dedicated to making sure we don't end up with our bones in some future museum. Their advice: no nukes! Instead, slam a spacecraft head-on into a dangerous rock to move it in a hurry, then fine-tune it with another spacecraft by using its gravity to pull the rock into a safe path. It sounds like sci-fi, but models show this is in fact our best bet to save the Earth.

Death by Exploding Star

Supernova 1987A
(X-ray: NASA/CXC/PSU/S.Park & D.Burrows.; Optical: NASA/STScI/CfA/P.Challis)

When a massive star ends its life, it does so with a bang: a supernova, which sends death sleeting across space in the form of high-energy radiation. Numerous studies indicate that a supernova would have to be closer than about 75 light years to do us any harm. The good news: no stars that close are capable of the deed. But in the past things were different; there's evidence we got caught in a blast 2 to 3 million years ago. Of course, the fact that we're still here means we survived. And it'll be some time before another such event occurs. That's good: there's not a darn thing we could do about it anyway.