On Oct. 12, a house-size asteroid will pass quite close to Earth – only 26,000 miles (42,000 kilometers) away. This is just above the orbital altitude of communications satellites and a little over one-tenth the distance to the Moon. But not to fear, it has no chance of hitting Earth.
Asteroid 2012 TC4 was discovered almost 4 years ago to the day, on October 4, 2012, just a week before it made another close pass by Earth.
With a little more advance notice this time around, NASA and asteroid trackers around the world are using the close pass to test their ability to operate as a coordinated International Asteroid Warning Network. This is a growing global observing network to communicate and coordinate their optical and radar observations in a real scenario.
“Asteroid trackers are using this flyby to test the worldwide asteroid detection and tracking network, assessing our capability to work together in response to finding a potential real asteroid-impact threat,” said Michael Kelley, program scientist and NASA lead for the TC4 observation campaign. You can read more details about the observing campaign in our previous article.
You can watch it pass by too, if you have a at least an 8 inch telescope, according to our David Dickinson, who has a very informative post about 2012 TC4 at Sky & Telescope.
Closest approach will be at on October 12, 2017, at 5:41 Universal Time (1:41 a.m. EDT).
You can also watch a couple of webcasts of the pass:
2012 TC4 is estimated to be 45 to 100 feet (15 to 30 meters) in size.
NASA’s Asteroid Watch says that no asteroid currently known is predicted to impact Earth for at least the next 100 years.