(Image from Wikipedia of known asteroids in our Solar System and size comparison)
Trajectory of asteroid 2017 001 which nearly hit the Earth on the 20th July 2017 https://gfycat.com/ifr/PerfumedNaturalAmericanalligator
In understanding that our true threats, as discussed in Anthropocentric survival: Killer Asteroids, are from Nature (not from within the human race), more so as the late Carl Sagan was once said “The universe seems neither benign nor hostile, merely indifferent. ” It could be now argued that ‘indifference’ could be seen as hostility. Yes, we have the potentiality to destroy ourselves, but the Universe could not only destroy humanity but remove all trace that we existed at all. As our telescopes and astronomical detectors become more precise. The realization that either life is rare or in a speculative sense via the Fermi Paradox, advanced alien life has moved on or away from a Universe, which in all retrospect, is anti-life.
“An asteroid flew pretty close to Earth last week. It missed us, you may have noticed. But we didn’t spot it until three days after it had flown past, which is a pretty terrifying reminder about the dangers asteroids pose to our world. Asteroid 2017 001 was about 37 to 77 meters (121 to 252 feet) across. It came about a third as close as the Moon, 123,031 kilometers (76,448 miles) from our planet, which is a pretty safe distance. It flew past at some point in the night of July 20 at a speed of about 10.36 kilometers (6.4 miles) per second. However, it was not until July 23 that we spotted the asteroid, after it had passed Earth, thanks to the ATLAS-MLO telescope in Hawaii. That’s, you know, not great. “Asteroid 2017 OO1 is an important reminder that we need to do a better job at detecting even small-sized asteroids early,” Grigorij Richters, the founder of Asteroid Day that seeks to raise awareness about asteroids, told IFLScience. “Small asteroids can cause significant regional damage and we are the only species that can do something about this cosmic hazard. Just ask the dinosaurs!”
“…For a bit of comparison, the Chelyabinsk meteor that exploded over Russia in 2013 was about 20 meters (65 feet feet) across. That injured hundreds, and caused considerable damage including shattering windows.In 1908, the famous Tunguska meteor – measuring 50 to 100 meters (165 to 330 feet) across – exploded over Siberia. It flattened about 80 million trees over an area of 2,000 square kilometers (770 square miles), although fortunately no one was killed. That’s almost the area of Luxembourg.”