Knowns and unknowns on asteroids
“The largest near-Earth asteroids (> 1 km diameter) have the potential to cause geologic and climate effects on a global scale, disrupting human civilization and perhaps even resulting in extinction of the species,”write Gerhard Drolshagen, Lindley Johnson and Romana Kofler(their text also published in the report Global Catastrophic Risks 2022).
The asteroid that passed the other week was medium-sized, about one kilometer wide, and missed Earth by a distance of 45 million kilometers – twelve times the distance to the moon. That is far away, even by astronomical standards.
When scientists looked at the asteroid, named 2005 YY128, it was classified, as Nasa defines it, as a Potentially Hazardous Asteroids (PHAs).
In the Global Challenges Foundation’s latest risk-report and the chapter on asteroid impact the authors write: “Smaller NEOs [near-Earth objects] in the 140-meter to 1-km size range could cause regional up to continental devastation, potentially killing hundreds of millions.”
To add, research has shown that the dinosaurs lived in prosperity, until they suddenly died out as a result of a meteorite impact, research shows. It is one of the global catastrophes that we can actually know has happened.