An asteroid about the size of a football field is expected to zoom by Earth on Tuesday, but at a safe distance, the United States space agency said.
The space rock was discovered as far back as 2010, but only recently did astronomers determine it would not collide with our planet, instead passing at a distance about halfway between the Earth and the moon.
Asteroid 2010 WC9 will make a “close approach” to Earth at 22:04 GMT, Nasa said, noting its closest pass will be over the coast of Antarctica.
“At the time of closest approach, the asteroid will be no closer to Earth’s surface than about 120 000 miles [193 000km],” the space agency said.
A good viewing spot for those equipped with a moderate, eight-inch telescope might be Cape Town.
The asteroid is believed to be about 60m to 120m across.
Its speed should clock in at about 12.9km a second.
Nasa said this approach will be the closest to Earth — for this particular asteroid — for at least two centuries.
Next year, on October 17, the asteroid will make a distant flyby of Earth at 42.8-million kilometres.
More than 10 000 asteroids are known to be orbiting near Earth, and scientists regularly keep track of them to monitor for potential strikes. — AFP