For astronomers, February 15 was a rather exciting day: we were buzzed by asteroid DA14 and had an unexpected visit from a meteorite over Russia. The internet, broadly speaking, took a more apocalyptic view of the day's events: one rock from space came smashing into the planet, and we narrowly missed colliding with another. There’s something about asteroids and meteorites that really brings out the conspiracy theorists and sensationalist news reports. And some floating around the web last week were pretty brilliant.
Here’s what actually happened: In 2012, astronomers found an asteroid (DA14), started tracking its orbit, and predicted it was going to pass about 17,000 miles above the Earth on Friday, February 15, 2013. Lo and behold, physics works, astronomers were right, and we got exactly the close pass we expected when we expected it.
The Russian meteorite, on the other hand, came as a surprise. It was roughly the size of an average house and came in fast, many times faster than a bullet shot from a rifle. A hole about 30 feet across was found in the surface of a frozen lake west of Chelyabinsk, the expected impact site of at least the main fragment of the meteorite.
Now, the fact that a house-sized meteorite struck unannounced is at least cause for a reappraisal of our meteor-monitoring tech. At the same time, a meteorite colliding with Earth is a random occurrence; it's not a sign that aliens or supernatural beings are planning on destroying the Earth. But that didn't stop people from proclaiming doomsday was at hand.