1. Is that really true? That "many scientists had thought that plate tectonics existed nowhere
in our solar system but on Earth." Why is stuff reported like that? What's wrong with saying, "Don't know."
There's a lot about planets we are only just discovering now. I'm okay with saying "I don't know yet" and I'm sure there are "many scientists" who think it's okay to. We'll get there...just no shortcuts.