What Makes Up the Solar System? Lesson 5-2 What Makes Up the Solar System?

Solar System – made up of a star (the sun) and all planets and other objects that revolve around that star. A. Includes 9 Planets 1. Planet – body that revolves around a star 2. Force of gravity between the star and planet holds the planet in orbit 3. Most planets have moons or satellites a. Satellite – body that revolves around a planet 4. “My Very Excellent Mother Just Sent Us Nine Pizzas”

B. Inner Planets – all rocky and dense 1. Mercury: a. closest to sun b. size of Earth’s moon c. no atmosphere – covered with craters and dust 2. Venus: a. Brightest object in the night sky (after the moon) b. same size as Earth

3. Earth: a. only planet known to support life b. atmosphere keeps temperatures so that living things can survive 4. Mars: a. red planet – reddish soil b. atmosphere is mostly Carbon Dioxide

C. Outer Planets 1. Jupiter: a. largest in solar system b. has a ring & dozens of moons c. can be seen w/out a telescope 2. Saturn: a. has rings made of ice, dust, boulders and frozen gases b. has dozens of moons

3. Uranus: a. has many moons and rings b. rotates on an axis that is tilted more than other planets 4. Neptune: a. several rings and moons b. strongest winds in solar system c. same size as Uranus 5. Pluto: a. small and rocky b. has an unusual orbit

D. Asteroids – chunks of rock too small to be called planets 1. found in the asteroid belt between Mars and Jupiter E. Meteors – pieces of rock that travel through space 1. when one hits the Earth’s Atmosphere it burns a. bright streak of light b. “shooting star” 2. when one reaches Earth – called a meteorite

F. Comet – ball of ice, rock & frozen gases F. Comet – ball of ice, rock & frozen gases that orbit the sun in irregular paths 1. Made of 3 parts a. Nucleus – made of rock, gas and dust b. Coma – circle made of water vapor and gas around the nucleus as it begins to melt c. Tail – made of water vapor, dust and gas. As the comet gets closer to the Sun it gets longer. The solar wind pushes the tail away from the sun.