A BBC graphic that gives you some idea just how large Asteroid 2012 DA14 is.
The enormous lump of rock will pass just 17,200 miles from Earth in approximately 5 1/2 hours time. That’s VERY close. In fact it’s closer to the planet than many of our satellites.
We’re assured that there’s no threat of collision so don’t worry. However, perhaps worry about all the other big lumps of rock out there that we don’t know about. It’s a tad unsettling that we didn’t even know about this one until a year ago!