1. SPACE Chapter 4 6 th Grade Science

21. 4.6 Exploring the Solar System The sun is the center of our solar system The solar system is made up of the sun and all the heavenly bodies that orbit it. We have eight planets in our solar system

22. Inner Planets Mercury, Venus, Earth, and Mars These are made mainly of rocks and metals.

23. Outer Planets Jupiter, Saturn, Uranus, and Neptune. Made of mainly gases, liquids, or ice.

24. Moons Earth has one moon. Venus and Mercury are the only two planets that have NO moons.

25. 4.7 Our Earth The earth REVOLVES around the sun. One revolution (trip around the sun) takes earth 365 ¼ days. This is called a “solar year”

26. Rotation page 280 A rotation is the earth’s spinning on its axis. One rotation is completed in about 24 hours.

27. Atmospheric Filter Our atmosphere acts like a filter to keep earth a place where humans can live. The atmosphere is a blanket of air. It protects us from the sun’s harmful UV rays It also keeps earth warm because of the “green house effect.” This is when the heat is trapped on earth because of the atmosphere.

28. 4.8 The Mysterious Moon The moon is a natural satellite orbiting the earth. It’s surface is covered with craters (holes) that make it look like a sponge. The moon affects the tides of the oceans on earth. There are 8 phases of the moon.

29. 4.9 Smaller Space Travelers Asteroids are tiny worlds traveling around the sun. They range in size from a few 100 miles to a small house! Asteroids are usually spherical shape (like earth) Made up of metals and rocks

30. Comets: Icy travelers Comets are the size of asteroids They have a bright tail when the come near the sun It is made of frozen rock, dust, and ice. It begins to melt near the sun and this causes the beautiful tail. A famous comet is “Halley’s comet”

31. Meteors: Momentary Intruders Meteoroids orbit the sun and are much smaller than asteroids. If they enter the earth’s atmosphere they are called a shooting star. The small ones are burned up as it enters our atmosphere. Some large ones cannot be burned up in time and they hit earth.