Over the weekend, an asteroid the size of a Tesla flew within 3,000 kilometers of the Earth, marking the nearest fly-by the planet has ever recorded.

According to CTV News, the asteroid, which has been nicknamed ‘2020 QG’, would have been less than 3,000 kilometers above us at its closest brush with Earth -- lower than pretty much any other artificial satellites in orbit.

Still, the biggest news of the day was the fact that scientists didn’t even know the asteroid was coming.

Close Call

The celestial body was only spotted by NASA about six hours after it had approached the planet on Sunday.

“The asteroid approached undetected from the direction of the sun,” NASA Center for Near Earth Object Studies Paul Chodas told Business Insider. “We didn’t see it coming.”

However, experts say this is no cause for panic. After all, the rock wouldn’t have posed any danger to humans even if it did come in contact with the Earth. Because of its relatively small size, the 2020 QG would have simply exploded upon entering the atmosphere, leaving only minuscule pieces to reach the ground.

Still, the undetected near-miss is worrisome nonetheless, because the next one might not be as harmless. NASA’s explanation that more dangerous asteroids have snuck up on their telescopes in the past isn’t helping either. 

Admittedly, there are gaps in our monitoring of known near-Earth objects such as asteroids. If a bigger one slipped through these gaps, it could kill tens of thousands of people before NASA could even know an asteroid was nearby.

“There’s not much we can do about detecting inbound asteroids coming from the sunward direction, as asteroids are detected using optical telescopes and we can only search for them in the night sky,” explained Chodas. “The idea is that we discover them on one of their prior passages by our planet, and them make predictions yeards and decades in advance to see whether they have any possibility of impacting.”

Another One Coming

At times, though, such surveillance systems prove enough to prepare us for whatever’s coming.

This Thursday, for instance, an asteroid bigger than a double-decker bus will fly past Earth, coming even closer to the planet than the Moon. 
As reported by Daily Express, asteroid 2020 PY2 is currently traversing the solar system at about 17 kilometers per second. Given such speeds, we’re lucky the asteroid is not headed straight to our home planet.