Documentales sobre la formación de la Tierra

link: http://www.youtube.com/watch?v=-1J5KPKF1jc








link: http://www.youtube.com/watch?v=FgdBE127FCQ










link: http://www.youtube.com/watch?v=B-m1gx0s0Ro








link: http://www.youtube.com/watch?v=EBOkGw2XMs8