Asteroid Will Pass Earth On Monday

By: Rob Adams
06/25/2011 10:36 AM ET

NASA is preparing for Asteroid Monday and astronomers are setting up their telescopes. The space agency has recalculated the time of closest approach for Monday to be about 3 1/2 hours later than initially reported. The small asteroid is about the same size as a tour bus and will make an extremely close pass by the Earth.

The event poses no threat to the planet. It will make its closest approach at 1:14 p.m. EDT (1714 GMT) on June 27 and will pass just over 7,500 miles (12,000 kilometers) above the Earth’s surface, NASA officials say. At that particular moment, it will be sailing high off the coast of Antarctica, almost 2,000 miles (3,218 km) south-southwest of South Africa. Asteroid Monday has been named 2011 MD.

Asteroid 2011 MD was discovered Wednesday (June 22) by LINEAR, a pair of robotic telescopes in New Mexico that scan the skies for near-Earth collisions. The best estimates suggest that it’s between 29 to 98 feet (9 to 30 meters) wide. An object of this size can be expected to come this close to Earth about every 6 years or so.

“There is no chance that 2011 MD will hit Earth but scientists will use the close pass as opportunity to study it w/ radar observations,” astronomers with NASA’s Asteroid Watch program at JPL wrote in a Twitter post Thursday (June 23). Even if it were to enter Earth’s atmosphere, it wouldn’t reach the surface, they added. Scientists say that if it got too close to the Earth, it would break up in Earth’s atmosphere and not cause ground damage.

For several hours prior to its closest approach, 2011 MD will be visible in moderately-large amateur telescopes. But despite its close approach, actually seeing this asteroid will not be an easy task. “These objects are so small (10 meters) that normally a sizeable telescope is required,” scientists warned. You will need to have access to an excellent star atlas, and because it will be moving so rapidly you’ll also need the very latest data from the Minor Planet Center to track its precise course against the background stars.