Astronomers just announced the discovery of seven Earth-sized transiting planets around TRAPPIST-1! Cool Worlds Lab astronomer Moiya McTier explains why this is so exciting, what we know and don't know so far, and what the prospects for life are in this fascinating system. ::More about this Video:: ► Gillon et al. (2017), "Seven temperate terrestrial planets around the nearby ultracool dwarf star TRAPPIST-1": http://www.nature.com/nature/journal/v542/n7642/full/nature21360.html ► O'Malley-James & Kaltenegger (2017), "UV Surface Habitability of the TRAPPIST-1 System": https://arxiv.org/abs/1702.06936 ► TRAPPIST-1 website: www.trappist.one ► Moiya McTier's website: http://moiyamctier.weebly.com ► Outro music by Taylor Davis: https://www.youtube.com/watch?v=dl9kI1yQKZk ::Playlists For Channel:: Latest Cool Worlds Videos ► http://bit.ly/NewCoolWorlds Cool Worlds Research ► http://bit.ly/CoolWorldsResearch Guest Videos ► http://bit.ly/CoolWorldsGuests Q&A Videos ► http://bit.ly/CoolWorldsQA Science of TV/Film ► http://bit.ly/ScienceMovies ::Follow us:: SUBSCRIBE to the channel http://bit.ly/CoolWorldsSubscribe Cool Worlds Lab http://coolworlds.astro.columbia.edu Twitter https://twitter.com/david_kipping Instagram https://www.instagram.com/cool.worlds THANKS FOR WATCHING!!