The space rock, 388945 (2008 TZ3), is about 490m wide — bigger than New York’s Empire State Building, which is around 440m tall — and has been classified as a “potentially hazardous asteroid” due to its predicted close passes.
For comparison, researchers have estimated that the meteor that likely caused the 1908 Tunguska event in eastern Siberia, flattening entire forests, may have measured around 100m to 200m in diameter, while the one that wiped out the dinosaurs was about 10km to 15km wide.
Space experts say 388945 (2008 TZ3) is roughly about 0.219 to 0.490 km in diameter.
While an asteroid that big could cause devastating damage if it hits Earth, Nasa scientists estimate that it will only make a “close approach”, passing by the planet at a distance of about 4 million km on Sunday.
The distance between the Earth and the moon, for comparison, is around 385,000km.
This is not the first time this particular asteroid has zoomed past Earth. In May 2020, the giant space rock passed by the planet at a distance of about 2.75 million km. It is not expected to come back that close to Earth until May 2163.
The asteroid routinely passes by Earth while it orbits the sun every 732 days, coming as close as 1 astronomical unit (AU), or about 150 million km, and reaching as far as 2.21 AU from the star.
It is not unusual for such large asteroids to pass close to Earth.
Experts calculate that asteroids of about 100m diameter impacting the Earth could generate an explosive force 10 times that of the 14 January volcanic eruption in Tonga.
Any asteroid over a certain size that comes within about 7.5 million km of Earth is likely to be considered “potentially hazardous”, depending on its trajectory.