Keplerian Memes

The cosmic bait-and-switch of introductory astronomy courses! You sign up thinking you'll leisurely discuss planet types and star formations, but suddenly you're deriving the vis-viva equation at 11:08 PM while questioning your life choices. That innocent "let's talk about planets" quickly transforms into calculating orbital velocities with gravitational parameters and semi-major axes. The formula shown (ε = v²/2 - GM/r) is orbital energy conservation, which leads to that terrifying velocity equation below it. Nothing says "academic betrayal" quite like expecting cool space facts and getting slapped with Keplerian mechanics instead!