This is an artist impression obtained from The University of Warwick and The University of Cambridge shows a rocky and water-rich asteroid being torn apart by the strong gravity of the white dwarf star GD 61. (Warwick & Cambridge Universities via AFP/Mark A. Garlick)
An asteroid bigger than a city bus is on track to zoom by Earth Friday at a safe but close distance, less than one-fifth as far away as the Moon, NASA said.
"Asteroids of this size do not often approach this close to our planet -- maybe only once or twice a year," said Paul Chodas, manager of the Center for Near-Earth Object Studies at NASA's Jet Propulsion Laboratory.
Called asteroid 2018 CB, the space rock will shave by our planet at around 5:30 pm (2230 GMT), the US space agency said.
It will remain about 39,000 miles (64,000 kilometers) from Earth, which is less than one-fifth the distance to the Moon.
The asteroid is estimated to be between 50 and 130 feet (15 and 40 meters) in size.
"Although 2018 CB is quite small, it might well be larger than the asteroid that entered the atmosphere over Chelyabinsk, Russia, almost exactly five years ago, in 2013," said Chodas.
Another small asteroid, about the same size, also skimmed by Earth this week.
Asteroid 2018 CC passed Tuesday at 3:10 pm (2010 GMT) at a distance of about 114,000 miles (184,000 kilometers).
Both were discovered this month by astronomers at the NASA-funded Catalina Sky Survey (CSS) near Tucson, Arizona.