Why Does The Earth Have Layers?

...or why do we live on an onion made of magma?

Viewers like you help make PBS (Thank you 😃) . Support your local PBS Member Station here: https://to.pbs.org/PBSDSDonate

Subscribe to It's Okay To Be Smart: http://bit.ly/iotbs_sub

Thanks to Miles Traer and Mike Osborne for geophysics help on this one!

Why does Earth have a liquid core, and how do we know?
http://scienceblogs.com/startswithaba...

How many pennies would you have to stack to melt the one on the bottom?   / how_many_pennies_need_to_be_stacked_before...  

Why are the inner planets rocky and the outer ones are gas giants?
http://www.quora.com/Why-are-the-inne...

Produced for PBS Digital Studios

Joe Hanson - Host and writer
Joe Nicolosi - Director
Amanda Fox - Producer, Spotzen IncKate Eads - Associate Producer
Katie Graham - Director of Photography
Andrew Matthews - Editing/Motion Graphics
John Knudsen - Gaffer
Dalton Allen - Post-production Intern

Theme music:
"Ouroboros" by Kevin MacLeod

Stock images via Shutterstock

-----------
Join us on Patreon!
  / itsokaytobesmart  

Twitter
  / drjoehanson  
  / okaytobesmart  

Instagram
  / drjoehanson  
  / okaytobesmart  

Merch
https://store.dftba.com/collections/i...

Facebook
  / itsokaytobesmartpbs