1. Planets in Our Solar System Inner Planets

2. All inner planets are rocky and dense. Each is relatively small with few if any moons. They are located between the sun and the asteroid belt Mercury Venus Earth Mars

3. Mercury Closest planet to the sun Smallest planet (1/3 of the size of Earth) Revolves around the sun in 88 days (fastest in our solar system) Cratered surface and thin atmosphere Named after the mythical winged messenger god, Hermes, for its speed No moon or seasons Explored by Mariner 10 on 3 different fly-bys

4. Venus Second planet from the sun Considered as Earth’s twin since they are both similar in size Rotates on its axis VERY slow and clockwise (opposite of all other planets) Hottest planet due to sulfuric acid clouds trapping in heat No moon Named after the Roman goddess of love/beauty Explored by Mariner 10 fly-by and Russia’s Venera 3

5. Earth Third planet from the sun Largest inner planet Densest planet Composed of 70% water and 30% land; Only planet to support life Has moderate temperature range and has seasons The word “Earth” means ground 1 moon which may have been part of Earth but broke off during a collision

6. Mars Fourth planet from the sun About half the size of Earth Its surface is dry, rocky, iron-rich dust Believed to have water frozen into the land (permafrost) Has a large volcano called Olympus Mons 2 moons (Phobos and Deimos which could have been escaped asteroids) Named after the Roman god of war- Aries Explored by Mariner 6-9;Viking 1-2; Mars Landers, Orbitors and Rovers