On Nov. 30, 2010, astronomers discovered an asteroid that could be as large as one of the Great Pyramids of ancient Egypt. It passed within 9 million miles of Earth and then scientists lost track of it as it headed back to the outer solar system.
Asteroid 2010 WC9, up to 130 meters (426 feet) in diameter, was observed for too short of a time for astronomers to be able to predict when its orbit might bring it back to our neighborhood.
Now that same asteroid is back and about to buzz by us about 70 times closer than it did eight years ago. That puts it at about half the distance between the Earth and moon, making it one of the closest approaches ever observed of such a sizable asteroid.
London's Northbolt Branch Observatories, which helped to rediscover the asteroid, will be broadcasting the flyby live via Facebook.
Don't worry. The broadcast won't be like a countdown to the apocalypse. 2010 WC9 will sail by us safely at about 3:05 p.m. PT on Tuesday.
While this asteroid isn't a threat (this time) it does emphasize the need to keep a watchful eye on the sky to catalog and track as many space rocks as possible.
"There are lots of asteroids and comets in our solar system and it's impossible to predict the trajectories of all of these objects, but we need to try," University of Saskatchewan astronomy professor Daryl Janzen said in a news release Thursday.
Just last month,.
On the cosmic scale, these asteroids are large enough to do some damage if they were to impact Earth, especially near a populated area. But they aren't considered big enough to do the kind of catastrophic damage caused by the space rock believed to have wiped out the dinosaurs.
"There is an extremely low probability of the planet coming into contact with one of these large near-Earth objects in our lifetime, but there is really good evidence that it happened in the past and led to mass extinction on the planet," said Janzen. "So, although the probability is low, it's important to discover as many NEOs as we can, so that if one does enter into a collision course with Earth, we can try to do something about it."
Updated at 10:14 p.m. PT to correct the day of the Tuesday fly-by.
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