What Is a Dwarf Planet? | NASA Planetary Sciences

In this video from NASA, learn about the history of defining a planet, and examine how classification changes based on new knowledge. Our understanding of the solar system has evolved since the ancient Greeks, who first used the word planetes to distinguish the objects that moved against the backdrop of stars in the night sky. The discovery of Pluto and Eris rekindled the debate over what a planet is, and in 2006, the International Astronomical Union (IAU) issued definitions for planets and dwarf planets. However, the debate continues among scientists all over the world. This resource is part of the NASA Planetary Sciences Collection. CREDITS: https://www.pbslearningmedia.org/credits/npls12.sci.ess.eiu.whatisplanet/ License: https://www.pbslearningmedia.org/help/full-license-for-section-3c-of-terms-of-use-download-and-share/

LicenseCustom License

More videos by this producer

ScienceCasts: Taking the Wild out of Wildfire

A new NASA-funded tool is taking some of the ‘wild’ out of wildfires by making it possible for U.S. fire managers to better spot dangerous blazes. Visit http://science.nasa.gov/ for more. Active fire maps of the United States: http://activefiremaps.fs.fed.us Click here to see more videos: https:/

ScienceCasts: Amazing Sunset Sky Show

Venus and Jupiter are converging for a must-see close encounter at the end of June. It could be the best backyard sky show of 2015. Visit http://science.nasa.gov/ for more. Click here to see more videos: https://alugha.com/NASA This video is from 2015