Scientists are just now unlocking the amazing secrets of how rain is made; some raindrops form around micrometeorites from outer space, others are created by bacteria that float into the upper atmosphere.
Which places on earth are poised to generate the next mega-tsunamis and the science of what happens as the wave emerges from open ocean and bears down on land.
Explore what drives the strange science behind places like Canada's Bay of Fundy-where water levels rise as much as 50 feet during high tide, and Alaska's Turnagain Arm, where 10-foot tall "bore waves" routinely wash in from the sea.
NASA satellites have mapped Earth's gravity and discovered mysterious spots where gravity is weaker; how earthquakes change the planet's gravitational field.
