This is a series of questions about Earth. The answers to any of these questions can be looked up in seconds; I ask that you don't do that. I want to check if people tend to know these things off the top of their head, and what their best guess is if they don't. Please don't look up any facts you don't already know in the course of answering, but if you want to do maths to guide your guess, feel free. Write up your answers however you want and in whatever units you want. Except the one question where it'd be cheating to answer in AUs, please use some other unit for that one.