ASTEROID FLYBY: Newly-discovered asteroid 2011 MD will pass only 12,000 kilometers (7,500 miles) above Earth's surface on Monday June 27 at about 9:30 a.m. EDT. NASA analysts say there is no chance the space rock will strike Earth. Nevertheless, the encounter is so close that Earth's gravity will sharply alter the asteroid's trajectory:
At closest approach, 2011 MD will pass in broad daylight over the southern Atlantic Ocean near the coast of Antarctica. As the asteroid recedes from Earth, it will pass through the zone of geosynchronous satellites. The chances of a collision with a satellite or manmade space junk are extremely small, albeit not zero.
Judging from the brightness of the asteroid, it measures only 5 to 20 meters in diameter. According to JPL's Near Earth Object Program office, one would expect an object of this size to come this close to Earth about every 6 years on average. For a brief time, it will be bright enough to be seen even with a medium-sized backyard telescope.