Asteroid to make close Earth approach

Added by on November 8, 2011

Asteroid 2005YU55 as of 1945UTC on November 8 2011; the asteroid is expected to pass Earth at about 324,600km on Tuesday

Asteroid 2005YU55, a 400m wide asteroid, will make a close approach to Earth on Tuesday at 23:28 UTC/GMT – the asteroid is not going to be close enough to cause any danger to Earth, yet scientists around the world are treating it as an unprecedented scientific opportunity.

At its closest, the asteroid is expected to be 324,600km (201,700mi), from Earth as measured from the center of the Earth. The distance between the Earth and the point at which the asteroid closest is 85% of the distance from the Earth to the Moon. The asteroid will be located up, about 300,000km, above the coast of Guatemala during its closest approach.

The asteroid is about 400m (1,300ft) wide which means that it will not have any gravitational influence on Earth – so it won’t affect tides and it won’t affect tectonic plates. This is the closest encounter with Earth during the past 200 years, and its next close-encounter is expected in 2075, yet another similar sized asteroid is expected in 2028.

The space rock will be tracked by amateur and professional astronomers around the wold, yet the best viewing will be in North America. NASA will take the opportunity to use the Goldstone Deep Space Complex and antennas at the Arecibo Observatory – both radio telescopes – to create detailed images of the asteroid’s features. NASA says data from the radio telescopes provide a resolution of about 2m (7ft) per pixel – which is comparable to the resolution provided by a spacecraft flying past the asteroid.

While the asteroid’s surface is about as dark as charcoal, it is expected to reach magnitude 11, making it possible for some backyard astronomers to view it through some telescopes.

The asteroid is expected to provide best visibility for about 10 hours, starting at 20:00 UTC on Tuesday November 8.

Scientists have been preparing for this event for months since they missed their last chance to see an asteroid this close to Earth in 1976. Scientists only realized in 1976 that they has missed the opportunity to get an up-close view 24h after the asteroid passed by.

Live tracking and analysis of the asteroid are available via: