Humans have walked the Earth for 190,000 years, a mere blip in Earth's 4.5-billion-year history. A lot has happened in that time. Earth formed and oxygen levels rose in the foundational years of the Precambrian. The productive Paleozoic era gave rise to hard-shelled organisms, vertebrates, amphibians, and reptiles. Dinosaurs ruled the Earth in the mighty Mesozoic. And 64 million years after dinosaurs went extinct, modern humans emerged in the Cenozoic era. The planet has seen an incredible series of changes—discover them for yourself.
The Innovators Project
Meet some of science's most important movers and shakers—from past and present.
How to Feed Our Growing Planet
National Geographic explores how we can feed the growing population without overwhelming the planet in our food series.
A new study on marmoset monkeys offers some hints about the causes of stillbirth.
The Titan Missile Museum gives an insider's look at what might have happened if the Cold War had turned into World War III. Video.
Shop Our Space Collection
The updated companion book to Carl Sagan's Cosmos, featuring a new forward by Neil deGrasse Tyson is now available. Proceeds support our mission programs, which protect species, habitats, and cultures.