What exactly is a planet? Is it size or composition or even its gravitational pull? Even the scientists cannot decide. Make your own decision by using these web sites. Included are eThemes resources on Pluto, the solar system, planetoid Sedna, and asteroids.
These sites are about the solar system and the eight planets. Find out how much you weigh or how old you would be on different planets. Learn about the planets' different climates and structures. Includes simulations, videos, and photographs.
Learn about Pluto, the dwarf planet. Read how this dwarf planet was formed, its geological formation, and planned missions to Pluto. Students and teachers can read articles on Pluto's demotion to dwarf planet. Includes many photographs.
Learn how and when the new planetoid Sedna was discovered. Read about different theories and mysteries surrounding the planetoid and its hypothetical moon. Includes graphics, photographs, and an animation.
Learn about asteroids in the Asteroid and Kuiper Belts. Learn about history of their discoveries, their composition, and orbits. Find out what materials can be mined in the future on asteroids surfaces. These sites contain photographs, diagrams, coloring pages, a movie and worksheet.