The agency put out a tweet this past Friday stating that, on September 1, asteroid 2011 ES4 will miss Earth by 45,000 miles, which is close when you consider the universe is unfathomably massive. They also dumbed it down for stupid people (me) by putting it into the perspective of how many football fields it's going to miss us by:
Pointing out that people will not end up like the dinosaurs, at least for the moment, astronomer Dr. Tony Phillips said “On Sept. 1st, asteroid 2011 ES4 will fly through the Earth-Moon system only 72,000 miles from Earth—close, but there is no danger of a collision.” Note that, even if you did click that link and saw that Phillips wrote about a collector's item Captain Kirk bobblehead just four paragraphs afterward, he's a professional who knows what he's talking about.
At the moment there is uncertainty over the incoming asteroid's size and orbit. This is irrelevant in the short term but, in the bigger picture, may determine whether it will strike our planet at some point in the future.
Also in the short term, the bigger concern for earth inhabitants may be the asteroid that has a 0.41 percent chance of hitting the U.S. on November 2, the day before the presidential election.
However that asteroid is about NBA forward sized, 6.5 feet, and probably won't cause too big of an impact. Feel free to disregard it but, whatever, you've been warned: