Planetary scientist Dr. Susan Lederer of the Astromaterials Research and Exploration Science (ARES) Division at the NASA’s Johnson Space Center discusses the discovery of the TRAPPIST-1 extrasolar system. Lederer also discusses the potential habitability of the seven planets orbiting the parent star. This was the fifth and final presentation in the Lunar and Planetary Institute’s 2017–2018 Cosmic Exploration Speaker Series, “Diving into Ocean Worlds.”