Ice Moon Enceladus - Sean sets up a sno-cone stand to help raise money to send a spaceship to Mars. But it's the hottest day of the year and he quickly runs out of ice, and he can't find any nearby. Then Jet has an idea where they can go to get some ice-Saturn's ice moon, Enceladus! Curriculum: Enceladus is a small moon of Saturn that contains a liquid ocean underneath an outer layer of ice. It has "ice volcanoes" that shoot geyser-like jets of water vapor into space. Some of the water vapor falls back as "snow" and the rest escapes, which supplies most of the material making up Saturn's E ring. What Goes Up... - Jet builds a mini-flying saucer in his garage and wants to test it, but to succeed, he has to learn what gravity is and how it works. Curriculum: Gravity is an invisible pulling power that every object has-planets, moons, stars, and YOU. Gravity pulls all objects in the universe toward one another. The bigger and heavier an object is (the more mass it has), the more gravity it has.