Pluto is tiny, icy, and used to be the ninth planet in the solar system. Used to be. So why isn’t Pluto a planet anymore? Join Molly and co-host Momo as they learn Pluto’s history, talk to planetary scientist Kelsi Singer about NASA’s New Horizons mission, and even hear from the planet itself. All that plus a nifty new mystery sound! This episode was sponsored by: Indeed (Indeed.com/BRAINS) - Claim your $75 sponsored job credit to upgrade your job post. Terms and conditions apply. Factor (Factormeals.com/brainson50) to get 50% off. IXL (IXL.COM/FIELDTRIP) to get a 20% off an IXL membership.Do you have your Smarty Pass yet?? Get yours today for just $4/month (or $36/year) and get bonus episodes every month, and ad-free versions of every episode of Brains On, Smash Boom Best, Moment of Um, and Forever Ago. Visit www.smartypass.org to get your Smarty Pass today!