Asteroids ploughing into Earth is something we hope to avoid. Imagine if such an impact happened in one of our major cities, the effects would be catastrophic. That's why there are such inventions as NASA's ion engine, for instance.
So when an asteroid roughly the size of a car rushed close by to our planet on Sunday and nobody noticed until after the fact, the news is rather worrying.
It came a mere 1,830 miles (2,950 km) by Earth, as per Business Insider.
Even if the asteroid had had an impact with Earth, given its size it wouldn't have made any huge damage — what's worrying is that no one saw it coming until it had already passed by.
"The asteroid approached undetected from the direction of the sun," Paul Chodas, the director of NASA's Center for Near Earth Object Studies, told Business Insider. "We didn't see it coming."
It was the Palomar Observatory that first noticed the asteroid's path.
As Chodas mentioned "Yesterday's close approach is closest on record, if you discount a few known asteroids that have actually impacted our planet."
2020 QG flew over the Southern Hemisphere, and Tony Dunn on Twitter created a simulation to show its speed — 7.7 miles per second (12.4 km per second) — and it looks impressively close to Earth.
It is now known as 2020 QG.— Tony Dunn (@tony873004) August 17, 2020
Once the telescope readings came through they showed that the asteroid was about the size of a car, somewhere between six feet (two meters) and 18 feet (5.5 meters) wide.
If this asteroid had made impact with Earth, it would have most likely blown up in the atmosphere and not had a bigger effect on people than hearing some distant traffic sounds.
The issue with this asteroid was that it came from the sun's direction, and as Chodas told Business Insider, "There's not much we can do about detecting inbound asteroids coming from the sunward direction, as asteroids are detected using optical telescopes only (like ZTF), and we can only search for them in the night sky."
"The idea is that we discover them on one of their prior passages by our planet, and then make predictions years and decades in advance to see whether they have any possibility of impacting."