The earth almost had a possible significant impact from an asteroid on February 4 .. While these events occur all of the time, the troubling aspect of this most recent earth-danger was that it was only noticed hours before potential impact. Richard Kowalski at Mount Bigelow Observatory near Tuscon, Arizona found it, and quickly notified the rest of the scientific community.
The name: 2011 CQ1. It was small, only 6.5 to 10 feet across – but that still could have caused serious problems for wherever on earth it would have struck.
Some other sources for the news:
Space: Tiny Asteroid Zips Close By Earth
Universe Today: Small Asteroid Just Buzzed Earth
…with all of our modern technology and our advanced knowledge, we only notice a possible earth changing event hours before it hits.. Wow.