“BTW, all, just for context, it appears that 2019 OK is by far the largest asteroid [to] pass this close to Earth in the last century!” reads one subsequent email from Planetary Defense Officer Lindley Johnson. NASA experts determined that a combination of factors ultimately caused the agency to miss it, including the position of the moon, bad weather and the slow-moving nature of the asteroid. (https://www.huffpost.com/entry/nasa-internal-emails-asteroid-ok-2019_n_5d8402bbe4b0957256b3f555)
Wiki: “The object’s size is estimated at 57 to 130 metres (187 to 426 ft) across-”
“If 2019 OK had been around 100 m (330 ft) in diameter an Earth impact could have released as much power as the 50 megatons generated by Tsar Bomba. If 2019 OK had been around the middle of the size estimates it could have released the equivalent explosive energy of about 10 megatons of TNT similar to the 1908 Tunguska event that flattened 2,000 km2 (770 square miles) of forest land. If 2019 OK had been on the smaller size it still could have released over 30 times the energy of the atomic blast by Little Boy at Hiroshima.”
These city killer near misses happen all the time. It is the extraordinary one that is the problem. One of those big asteroids or comets is going to get us. Could be tomorrow and it could be even bigger than the one that killed the dinosaurs. Really. It would be just a spike in that probability curve everyone mistakes as safety. In hindsight we would remark it was out of the ordinary but considering the timescale not really extraordinary. Except no one would be left to make the comment.
The human race would be gone…forever.
Any alien race observing us would not be surprised.
We were just not intelligent enough to survive.