Russian President Vladimir Putin said this month that he is not bluffing about using nuclear weapons in Ukraine. As an astronomer, an immediate question came to my mind: If Putin were to follow on this threat and explode a tactical nuclear bomb, how far away from Earth would the flash of light be visible to a space telescope of an extraterrestrial civilization?
Frankly, I am worried that extraterrestrials will downgrade our intelligence if they realize that we are on the path to self-destruction. My response to the war in Ukraine resembles the reaction of a kid to a loud argument among his parents at home. It reflects the fear of what our cosmic neighbors might think if they notice the violence on our home planet.
To read more, click here.