A celestial trick will treat us all this Halloween, as a large asteroid – only discovered three weeks ago – will fly past the Earth at the closest distance in almost a decade.
The rock, named NEO 2015 TB 145, was first spotted on October 10 by a group of astronomers using the Pan-STARRS telescope in Hawaii. The asteroid measures 280 to 620 metres in diameter, making it about the size of a large modern skyscraper, and is moving at a velocity of 35km/s, which NASA scientists describe as “unusually high.”
NEO 2015 TB 145 will make its closest approach to the Earth on October 31, when it will pass the planet at a distance of 0.0032 AU, or 1.3 lunar distances. That breaks down to 479,000km, making the asteroid the closest object to fly past the Earth since 2006’s NEO 204 XP14 – which flew by at 1.1 lunar distances.
After the Halloween visit, no – as yet – known object will come as close to the Earth again until August 2027, when NEO 1999 AN10 will be at 1.0 lunar distance.
Despite its recent discovery, thanks in no small part to its “exceptionally eccentric and high-inclination orbit,” NASA says that the asteroid’s journey past the Earth poses no threat.
During the flyby, the asteroid will reach a magnitude luminosity of 10, so it should be observable to astronomers with telescopes, particularly those situated in the Northern Hemisphere. The bad news for star gazers is that the moon will be a relatively bright 80% waning gibbous at the time.
