Space, but explain like I'm five. The head of our Planetary Science Division, Dr. Lori Glaze, will answer questions from 3-4pm ET (2000-2100 UTC) about planets, moons and spaceships without a bunch of jargon. It's not rocket science, it's an #ELI5 #RedditAMA. Let's go! t.co/DBDIbRW43i