1. Chapter 18

2. Lesson 1 What Makes up the Universe? The universe is all of space and everything in it. The universe is all of space and everything in it. A Galaxy is a system of dust, gas, and many millions of stars held together by gravity. A Galaxy is a system of dust, gas, and many millions of stars held together by gravity. We live in the Milky Way Galaxy. The Milky Way is shaped like a flat spiral. We live in the Milky Way Galaxy. The Milky Way is shaped like a flat spiral.

3. Astronomy is the study of the Sun, Moon, stars, and the other objects in space. Astronomy is the study of the Sun, Moon, stars, and the other objects in space.

4. The Solar System The Solar System includes the Sun, the planets, their moons, and other objects. The Solar System includes the Sun, the planets, their moons, and other objects.

5. Gravity is the force that keeps Earth and other objects in their orbits Gravity is the force that keeps Earth and other objects in their orbits The Sun is so massive that its gravity pulls the planets toward it. The Sun is so massive that its gravity pulls the planets toward it. gravity video gravity video gravity video gravity video

6. Inner Planets Mercury Mercury Closest plant to the Sun. Closest plant to the Sun. Covered with craters or dents shaped like bowls Covered with craters or dents shaped like bowls Mercury is extremely hot during the day and is very cold at night because there is not an atmosphere to keep in the heat. Mercury is extremely hot during the day and is very cold at night because there is not an atmosphere to keep in the heat. The Mariner 10 is a space probe that visited Mercury in 1974. A space probe is a vehicle that carries cameras and other tools for studying different objects in space. The Mariner 10 is a space probe that visited Mercury in 1974. A space probe is a vehicle that carries cameras and other tools for studying different objects in space.

7. Venus Venus Venus rotates in the opposite direction than Earth. Venus rotates in the opposite direction than Earth. Venus has an atmosphere, but the clouds are poisonous. Venus has an atmosphere, but the clouds are poisonous. The clouds reflect the Sun’s light which makes it one of the brightest objects in the sky. The clouds reflect the Sun’s light which makes it one of the brightest objects in the sky.

8. Mars Mars 4 th planet from the Sun 4 th planet from the Sun Soil contains iron oxide, which gives it a reddish-brown color. Called the “Red Planet” Soil contains iron oxide, which gives it a reddish-brown color. Called the “Red Planet” Has 2 moons Has 2 moons Mars video 10 minutes Mars video 10 minutes Mars video 10 minutes Mars video 10 minutes

9. Gas Planets Jupiter—5 th planet from the Sun Jupiter—5 th planet from the Sun Gas gaint—a planet made of mostly gases Gas gaint—a planet made of mostly gases Largest planet in our solar system Largest planet in our solar system It is so large that if it was hollow inside all the other planets would fit inside. It is so large that if it was hollow inside all the other planets would fit inside. Has a large red spot which is actually a large storm. Has a large red spot which is actually a large storm. Has rings that are very dark and can not be seen from Earth. Has rings that are very dark and can not be seen from Earth. Video on Gas Planets (2:13 minutes) Video on Gas Planets (2:13 minutes) Video on Gas Planets (2:13 minutes) Video on Gas Planets (2:13 minutes)

10. Saturn 6 th planet from the Sun Saturn 6 th planet from the Sun Is a gas giant Is a gas giant Has large rings. The rings are made up of everything from dust to large boulders. Has large rings. The rings are made up of everything from dust to large boulders. Galieo saw the rings from earth and thought they were handles in the 1600’s Galieo saw the rings from earth and thought they were handles in the 1600’s Has 34 moons. Has 34 moons.

11. Uranus7 th Planet from the Sun Uranus7 th Planet from the Sun A gas giant A gas giant Rotates on its side Rotates on its side This is the largest planet you can see from earth with out a telescope. This is the largest planet you can see from earth with out a telescope. Atmosphere is made up of methane which is a liquid and gives Uranus its fuzzy blue-green look Atmosphere is made up of methane which is a liquid and gives Uranus its fuzzy blue-green look Has at least 27 moons Has at least 27 moons

12. Neptune 8 th Planet Neptune 8 th Planet Smallest of the gas planets, but it is still very large. It could hold 60 Earths inside if it was hollow. Smallest of the gas planets, but it is still very large. It could hold 60 Earths inside if it was hollow. Has strong winds that blow huge storms across the planet. Has strong winds that blow huge storms across the planet. Has at least 13 moons. One of its moons is the coldest body in our entire Solar System -235 C Has at least 13 moons. One of its moons is the coldest body in our entire Solar System -235 C

13. Magic School Bus Space Video (29 minutes) Magic School Bus Space Video (29 minutes) Magic School Bus Space Video (29 minutes) Magic School Bus Space Video (29 minutes)