In 2006, Pluto was reclassified as a “dwarf planet.” This had two main effects on our solar system: it reduced the number of recognized planets to eight, and left many Earthlings very sad. But Pluto’s demotion reignited a conversation that scientists have had since Neptune’s discovery: is there a “Planet X” orbiting the Sun that we don’t yet know about? <br /><br />--<br /><br />Producer/Video by: Jason Lederman<br /><br />Narrator: Eleanor Cummins<br />Music: APM Music<br /><br />Special Thanks: Br. Guy Consolmagno, IAU<br />Media: NASA, JPL, JPL-Caltech, ESO, Prelinger Archives, IAU, Pexels, Getty Museum, FreeSound.org, Buena Vista Pictures (The Hitchhiker’s Guide to the Galaxy)<br /><br />Additional Media:<br />ESA/Rosetta/NAVCAM (https://photojournal.jpl.nasa.gov/catalog/PIA19687)<br />NASA/Ames/JPL-Caltech (https://images.nasa.gov/details-PIA13833.html)<br />NASA/JPL-Caltech/Univ. of Arizona (https://images.nasa.gov/details-PIA22051.html)<br />NASA/JPL-Caltech (https://images.nasa.gov/details-PIA22098.html)<br />https://depositphotos.com/39943223/stock-photo-mercury-statue.html<br />https://depositphotos.com/82803476/stock-photo-the-goddess-of-love-aphrodite.html<br />https://depositphotos.com/67151135/stock-photo-god-of-war-mars-ares.html<br />https://depositphotos.com/82416024/stock-photo-portrait-of-zeus.html<br />https://depositphotos.com/223348754/stock-photo-god-saturn-statue-summer-garden.html<br /><br />CC-BY-4.0:<br />NASA/LROC/M.Kornmesser (https://www.eso.org/public/videos/moon_big_4k/)<br />ESO (https://www.eso.org/public/videos/eso1134a/)<br />NASA/ESA/M.Kornmesser (https://www.eso.org/public/videos/earth_2015_4k/)<br /><br />--<br /><br />FOLLOW POPULAR SCIENCE<br /><br />https://www.popsci.com<br /><br />Facebook: https://www.facebook.com/popsci<br /><br />Twitter: https://www.twitter.com/popsci<br /><br />Instagram: https://www.instagram.com/popsci<br /><br />Snapchat: https://www.snapchat.com/add/popularscience<br /><br />Pinterest: https://www.pinterest.com/popularscience
