2. Revolve? Revolve means for a smaller object to move around a larger object. Planets revolve around the sun.
3. Rotation Rotate is similar to spinning. When a planet rotates, its spins itself on its axis. The Earth Rotates
4. Difference between Inner and Outer Planets Inner planets are inside asteroid belt, Outer planets are outside of asteroid belt. Inner planets are smaller than outer planets Inner planets are mostly made of rock, outer planets are mostly made of gas.
5. Craters in inner planets? There are more craters in the inner planets because sun’s gravity attracts asteroids from the asteroid belts to the inner planets.
6. Orbit Orbit is the path a planet/satellite follows when it revolves around a larger object. This Satellite orbits around the sun.
7. A Planet A planet needs to have: Large enough so the gravity is strong enough to make the planet round Orbits around the sun Cleared out its path
8. Dwarf Planets Dwarf planets were declared to be the class of objects that have a large enough mass to become round due to gravity and are in orbit around the sun, but have not cleared out its orbital path around the Sun Pluto, Ceres, and Eris are the three dwarf planets.
12. Mercury Mercury is the closest planet to the sun Thin atmosphere due to weak gravity. Helium and sodium are found on its atmosphere. Impact cratering, volcanism, and tectonic activity shaped Mercury.
16. Mars Ancient bacteria and other small signs of life suggest that there was once life on Mars Atmosphere is mainly carbon dioxide Olympus Mons is a large volcano on Mars. Two satellites are Phobos and Deimos.
18. Jupiter Jupiter rotates very fast. This allows its poles to be flatter and round in the center. Hydrogen, helium, sulfur, and nitrogen make up its atmosphere. The Great Red Spot is a large hurricane on Jupiter. Jupiter has 63 satellites.
19. Saturn Hydrogen and helium make up Saturn’s atmosphere. Saturn’s rings are believed to be formed by its moons The ring is composed of dust and ice. Saturn could float in water due to its low density. Seasons in Saturn last 7 years.
20. Uranus Uranus tilts at 98 degrees. It seems like it rotates on one side. Hydrogen, helium, and methane make up its atmosphere. It has 27 known satellites.
21. Neptune Ammonia, helium, and methane make up its atmosphere. Neptune has 13 known satellites. Triton is Neptune’s largest satellite. Astronomers think that it was captured by Neptune’s gravity and forced it to revolve around Neptune.
22. Pluto Charon, Nix, and Hydra are Pluto’s three moons. Scientists learned using a spectroscope that there was methane frost on Pluto and water frost on Charon. Charon shares atmosphere with Pluto.
23. Ceres It takes 4.6 Earth years for Ceres to make one revolution. Ceres was once considered an asteroid because it was in the asteroid belt. Its surface is covered with a mixture of water ice, carbonates, and clays.
24. Eris Xena was Eris’ original name. It takes 557 Earth years for Eris to make one orbit around the sun. Dysnomiais Eris’s moon It did not clear out its orbit, so it could not be a planet.
25. THE END Bibliography: http://starchild.gsfc.nasa.gov/docs/StarChild/solar_system_level2/planets.html http://en.wikipedia.org/wiki/Planet
