Huge Asteroid 2005 YU55's Close Encounter With Earth

In April 2010, this radar image of the near-Earth asteroid 2005 YU55 was taken by the Arecibo radio telescope in Puerto Rico. 

On Nov. 8, 2011, this large space rock zips by Earth again and will be surveyed by radar, visual and infrared equipment.

CREDIT: NASA/Cornell/Arecibo

Skywatchers hoping to glimpse a huge asteroid as it flies close by Earth Tuesday (Nov. 8) will need the right equipment and a lot of luck to spot the faint and fast-moving space rock in telescopes, scientists say.

The interloping space rock, called asteroid 2005 YU55, will pass between Earth and the orbit of the moon on Tuesday (Nov. 8), but does not pose a threat to our planet, NASA scientists have said.

The asteroid is about the size of an aircraft carrier, spanning approximately 1,300 feet (400 meters), and is the largest space rock to have a close encounter with Earth with advance notice in 35 years.

Asteroid 2005 YU55 is expected to pass closest to Earth at a range of about 201,700 miles (324,600 kilometers) on Tuesday at 6:28 p.m. EST (2328 GMT). The average distance between the moon and Earth is about 238,854 miles (384,399 km).

Skywatchers around the world are gearing up for the event, but actually spotting the asteroid as it flies by Earth could be tricky, said Scott Fisher, program director of the National Science Foundation's Division of Astronomical Sciences.

Still, the asteroid flyby will be visible from the northern hemisphere, and Fisher offered some helpful tips in an NSF webchat on Nov. 3 organized by ScienceNow

The last time a space rock as big as 2005 YU55 came as close to Earth was in 1976, although astronomers did not know about the flyby at the time. 

The next known approach of an asteroid this large will be in 2028