Astronomers discover a massive asteroid that could hit us in 2032
George Dvorsky, io9, 17 October 2013 (hat tip: Big Picture)
Mark August 26th, 2032 on your calendar, folks. Ukrainian astronomers have just detected a 1,350-foot-wide (410 meter) minor planet that’s headed our way. The impact risk is minimal, but it’s now the most serious near-term celestial threat to face our planet.
As one commenter noted, that even a blast 50 times larger than the largest nuclear explosion set off (2,500 megatons) it is not an extinction event. Unless it happens to hit near you. As to the likely hood of it actually hitting the earth:
think [of it as a] grain of powder that will be at 10 meters from a mosquito as "almost hitting it", it will pass at almost 20 times the distance from earth to the moon.