The helpful geniuses at NASA explain that the chances of an impact are one in 63,000 — essentially, there is a 99.998% chance that it will miss us. Astronomers, however, haven't had enough time to study the near-Earth object's orbital path since it was discovered on October 8. As Phil Plait at Slate notes, "There are always some measurement uncertainties, making the calculated orbit fuzzy; what you get is a most probable orbit, which allows you to get a most probable position for the asteroid some time in the future. But really you get a big fuzzy volume of space it could very likely be in, and it gets bigger and fuzzier the further in the future you project it."
That's not to say that we needn't be concerned about a major impact event like Tunguska, which leveled over 830 square miles of Siberian wilderness in 1908. Over 10,000 near-Earth objects have already been discovered, according to NASA, with untold thousands likely still out there. Though statistically speaking, we're probably safe — this time around. (Slate)