First, we crack open some fossils, peer back into ancient seas, and look up at lunar skies to find that a year is not quite as fixed as we thought it was. Then, a deafening sex orchestra hits the East Coast -- billions and billions of cicadas crawl out of the ground, sing their hearts out, then mate and die. And we end 200 miles above Earth's surface, where astronaut Dave Wolf -- rocketing through the blackness of Earth's shadow at 5 miles a second -- floated out of the Mir Space Station on his very first spacewalk.