Most of the Earth is hot, molten metal and rock. In fact, the inhabitable part makes up less than 1% of the planet's mass. ➡ Subscribe: http://bit.ly/NatGeoSubscribe About National Geographic: National Geographic is the world's premium destination for science, exploration, and adventure. Through their world-class scientists, photographers, journalists, and filmmakers, Nat Geo gets you closer to the stories that matter and past the edge of what's possible. Get More National Geographic: Official Site: http://bit.ly/NatGeoOfficialSite Facebook: http://bit.ly/FBNatGeo Twitter: http://bit.ly/NatGeoTwitter Instagram: http://bit.ly/NatGeoInsta Known Universe: Cosmic Fury : http://channel.nationalgeographic.com/series/known-universe Understanding Earthquakes | National Geographic https://youtu.be/cavq2HFBa-U National Geographic https://www.youtube.com/natgeo