We live in a massive universe filled to its infinite brim with things that can destroy us. Sometimes we like to think our biggest problems are strictly "homegrown," so to speak. You know, things like the frequency of earthquakes steadily increasing or a massive volcanic eruption turning all of Britain into a no-fly zone.
But let's not forget that our little speck of green and blue is but a microscopic dot in an infinite void. A void that takes no prisoners. Just when you think you've got this whole life thing figured out, you hear about the biggest recorded explosion in the history of the known universe. A "super-supernova" of a giant star that created its own anti-matter and became a gigantic particle accelerator. How big, you ask? 4 megayottagrams. And how big is that? 400,000,000,000,000,000,000,000,000,000,000. That's 32 zeroes, there.
There's also the matter of the comet McNaught, which was discovered in 2007 but has recently been measured. It's the biggest comet measured to date. No word on whether or not it's heading straight for Earth. My guess is yes. After all, our planet seems to be a magnet for stuff from outer space that only wants to kill us all.