A 100-foot-wide asteroid is set to whiz by the earth this afternoon, and there's a chance we'll be able to watch it happen live. A Slooh Observatory telescope will be searching for the asteroid, and it's going to broadcast its imagery directly to YouTube. Slooh warns that the asteroid's small size and quick speed means there's a possibility that it won't catch it, but the asteroid's close proximity to Earth — just 217,000 miles away at its nearest — means there's certainly a chance of tracking it. You'll be able to begin watching the transmission at 4PM ET/1PM PT, and Slooh Observatory director Paul Cox will discuss what's being shown during the 15-minute broadcast.

NASA says that the asteroid will pass by the earth safely — an event that happens about 20 times each year.