It's debatable if we'd know. The Earth is really old. https://www.theatlantic.com/science/archive/2018/04/are-we-earths-only-civilization/557180/ https://www.t

It's debatable if we'd know. The Earth is really old. https://www.theatlantic.com/science/archive/2018/04/are-we-earths-only-civilization/557180/ https://www.theatlantic.com/science/archive/2018/04/are-we-e...