Asteroid in close encounter this Saturday
IT was discovered just last Sunday.
Asteroid 2018CB is due to pass above us at just 64,000km at about 9.30am AEDT on Saturday.
That's five times closer to Earth than the Moon.
There is no chance it will deviate from its course and strike our planet.
NASA's automated Catalina Sky Survey telescope detected two near-Earth objects earlier this week.
The first - Asteroid 2018CC - reached its closest point (184,000km) only 35 minutes before Elon Musk launched his Falcon Heavy Rocket on Wednesday.
Asteroid 2018CB is coming much closer.
Early indications are it's a lump of space debris somewhere between 12m and 38m across.
"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," manager of NASA's Center for Near-Earth Object Studies Paul Chodas said in a press release. "Asteroids of this size do not often approach this close to our planet - maybe only once or twice a year."
While there are millions of asteroids orbiting the Sun between Mars and Jupiter, rogue rocks and bundles of ice tend to only drift close to Earth only a few times each year.
The Chelyabinsk event was the explosion of a 17m large meteor over the southern Ural region in Russia. While it detonated in the atmosphere, the shockwave it produced damaged some 7200 buildings, with flying debris - mainly broken glass - injuring more than 1500 people.
Saturday's fly-by will be lifestreamed via the Virtual Telescope Project.
NASA's Planetary Defense Coordination Office is one of several organisations scouring Earth's skies for such space rocks. Each discovery is tracked and analysed, with the results recorded at the Small-Body Database.
NASA has been tasked with locating 90 per cent of "potentially hazardous near-Earth asteroids". These are defined as being at least 140 meters wide and passing about 7.48 million kilometres of Earth.