Source: Global News

An asteroid large enough to wipe out a city narrowly missed striking the Earth late Wednesday, unbeknownst to most people on a planet that might have been forever changed had it hit.

The massive space rock was approximately 100 metres wide and it flew past the Earth at a startling 24 kilometres per second, according to data from NASA. That’s 70 times the speed of sound, or roughly the same speed as the asteroid that wiped out the dinosaurs.

The object, dubbed Asteroid 2019 OK, missed the Earth by approximately 73,000 kilometres, placing it much closer to our planet than the moon.

Astronomers had been watching for three other asteroids to pass by the Earth on Wednesday when they noticed Asteroid 2019 OK appear seemingly out of nowhere. Researchers only spotted it a short time ago, but they didn’t confirm the discovery until a few hours before it passed.

“It’s a city killer,” Swinburne University astronomy professor Alan Duffy told the Sydney Morning Herald. “Because it’s so small it’s incredibly hard to see until right at the last minute.”

He added that it’s unusual for an asteroid of this size to pass inside the moon’s orbit.

“Definitely too close for comfort,” Duffy said.

Astronomers with The Ohio State University shared a graphic on Twitter of the near-miss.

Asteroids of this size are capable of triggering the equivalent of a large nuclear explosion if they hit Earth, according to Michael J. I. Brown, an astronomy professor at Monash University in Australia. Brown compared such an impact to the Chelyabinsk meteor that caused a major explosion in Russia in 2013. That meteor was approximately 20 metres in diameter.

“Under the wrong circumstances a meteor impact could devastate a city,” Brown wrote in a piece published by The Conversation on Thursday.

NASA says Asteroid 2019 OK was between 57 and 130 metres in diameter. That’s much larger than the 20 metre-wide Chelyabinsk meteor. However, both are pebbles compared to the asteroid that wiped out the dinosaurs, which is thought to have been about 16 kilometres across.

Brown says Asteroid 2019 OK was difficult to spot because it was coming from the direction of the sun.

These near-misses only occur once every few years, but humans should be paying more attention to the potentially devastating threat they pose, Duffy says.

He described the asteroid as a “timely reminder” that these threats are out there in a tweet on Thursday.

“Sooner or later one will have our name on it,” Duffy wrote.