Planetary scientist Carolyn Porco shows images from the Cassini voyage to Saturn, focusing on its largest moon, Titan, and on frozen Enceladus, which seems to shoot jets of ice.

Watch it till the end

Michael Shermer says the human tendency to believe strange things -- from alien abductions to dowsing rods -- boils down to two of the brain's most basic, hard-wired survival skills. He explains what they are, and how they get us into trouble.

Waves inside a water sphere and Water droplets in a Bubble in a sphere