Excerpt:
Astronomers discovered the nearby asteroid, named 2002 NY40--not to be confused with better-known 2002 NT7--on July 14th. It measures about 800 meters across, and follows an orbit that ranges from the asteroid belt to the inner solar system. On August 18th, the asteroid will glide past our planet only 1.3 times farther away than the Moon.
"Flybys like this happen every 50 years or so," says Don Yeomans, the manager of NASA's Near-Earth Object Program office at JPL. The last time (that we know of) was August 31, 1925, when another 800-meter asteroid passed by just outside the Moon's orbit. In those days there were no dedicated asteroid hunters--the object, 2001 CU11, wasn't discovered until 77 years later. At the time of the flyby, no one even knew it was happening.
2002 NY40 is different. We know the asteroid is coming, and astronomers have time to prepare.
Interesting article, Callisto. Thanks for the post & ping !
I've got a good pair of binoculars, too. I'll be checking this out. 
Please let me know if you want ON or OFF my General Interest ping list!. . .don't be shy.