TIL about the Drake Equation which estimates the odds of existing E.T.
https://www.space.com/25219-drake-equation.html
It's an interesting equation, and in my opinion valuable to think about... however, as the Wikipedia article on it notes it has such a wide range of possible answers that it's probably useless.
From https://en.wikipedia.org/wiki/Drake_equation: "a low estimate [yields] N = 9.1 × 10^−11... On the other hand [using] higher values that have been proposed [yields] N = 15,600,000."
(where N represents the number of E.T. civilizations in our galaxy with which communication might be possible)