If you think about the whole history of our planet, the part that includes humans is just a teeny tiny blip. The Earth was around for more than four BILLION years before there was any life on the planet at all. Thinking about such a huge amount of time can really boggle your brain!  How do we understand what happened when?  We asked astronomer Mark Popinchalk to help us find the answer.

Got a question that totally rocks? Send it to us at BrainsOn.org/contact, and we’ll help reach a geo-LOGICAL conclusion.