This is a rebroadcast of one of our favorite episodes from the past! It’s a scientific controversy of planetary proportions! Is Pluto a planet, or not? You decide, after we present two sides of an epic astronomy argument. Back in 2006, the International Astronomer’s Union voted on a definition of the word “planet” that excluded Pluto and other newly dubbed “dwarf planets” from planethood status. Astronomers - and everybody else - quickly chose sides. We dive deep into the debate and learn that Pluto’s not the only Space Object Formerly Known As A Planet. Then we’ll ask you to weigh in with your opinion, and see if you can find “consensus” on what should be called a planet. Featuring planetary astronomer Kirby Runyon. We have a present for your birthday!! We’ll be doing birthday shoutouts for our Patreon members, beginning next month. Want to hear a message on the podcast just for your special day? Pledge at the $5 level at patreon.com/tumblepodcast. You’ll be helping us make the show, and we also have extra audio goodies for you. Hear more from our interviews with scientists! For this episode, Kirby Runyon expands on the different types of planets, and the fascinating features you can find on each one. There’s more about planets, on our website at sciencepodcastforkids.com. Don’t forget to subscribe to Tumble and tell your friends! See the new "Eight Planets in the Solar System" video here.