Here's Why Astronomers Did Not Detect The Russia Meteor Ahead Of Time• Business Insider
Less than 24 hours later, a larger asteroid, 2012 DA14, passed safely above Earth at a distance of around 17,200 miles, the closest an object of that size has come to our planet since scientists began monitoring the skies. Astronomers had been tracking that asteroid for about a year and knew that it posed no danger of colliding with Earth.
NASA held a teleconference this afternoon to discuss both events.
Here's what they know so far:
The Russia meteor is estimated to have been about 50 feet in diameter, which is considered a tiny asteroid, according to meteor expert Bill Cooke.