2. Our Solar System A Write On Activity

3. EARTH AND SPACE SCIENCE Tennessee Standard: Content Standard: 7.0 Earth and Its Place in the Universe The student will investigate the structure of the universe. Learning Expectations: 7.1 Recognize the basic components of the universe.

4. Our Solar System Our solar system is made up of: Sun – Star in the center of a solar system. Nine planets Their moons – a natural satellite that orbits a primary planet. Asteroids Comets

5. 4 Terrestrial vs. Gaseous Planets Terrestrial Mercury, Venus, Earth, Mars Mercury, Venus, Earth, Mars 1. Rocky  More dense 2. Smaller 3. More closely spaced 4. Closer to the Sun Gaseous Jupiter, Saturn, Uranus, Neptune Jupiter, Saturn, Uranus, Neptune 1. Gaseous, has more He and H  Less dense (Saturn would float) 2. Larger 3. Spaced farther apart 4. Farther from the Sun

6. Inner Planets The inner four rocky planets at the center of the solar system are: Mercury Venus Earth Mars

7. Mercury Planet nearest the sun Second smallest planet Covered with craters As a result of having no atmosphere to protect it from foreign objects hitting its surface. Has no moons or rings About size of Earth’s moon

8. Venus Sister planet to Earth Has no moons or rings Hot, thick atmosphere High composition of CO2 Very hot Brightest object in sky besides sun and moon (looks like bright star) Covered with craters, volcanoes, and mountains

9. Earth Third planet from sun Only planet known to have life and liquid water Atmosphere composed of composed of Nitrogen (78%), Oxygen (21%), and other gases (1%). Due to its position in the solar system relative to the sun and composition of atmosphere it makes it an ideal planet for supporting life.

10. Mars Fourth planet from sun Appears as bright reddish color in the night sky Surface features volcanoes and huge dust storms Has 2 moons Most studied planet other than earth. This is because its characteristics are closest to being able to support life.

11. ASTEROID BELT Most asteroids can be found in the Asteroid Belt, which is located between Mars and Jupiter. Asteroids are rocky and metallic objects that orbit the Sun, but are too small to be considered planets. They are known as minor planets. Asteroids range in size from Ceres, which has a diameter of about 1000 km, down to the size of pebbles.

12. Asteroids Small bodies Believed to be left over from the beginning of the solar system billions of years ago 100,000 asteroids lie in belt between Mars and Jupiter Largest asteroids have been given names

13. Meteoroids and Meteorite Meteoroids are loose dust particles that come from Comeroid. Most are Very small. When it enters Earth’s atmosphere it forms a bright light, a shooting star. Most meteoroids break up in the Earth’s atmosphere. When they break up it is called a meteorite.

14. Comets They are like dirty snowballs Small icy bodies Travel past the Sun Give off gas and dust as they pass by

15. Outer Planets The outer planets composed of gas are : Jupiter Saturn Uranus Neptune

16. Jupiter Largest planet in solar system Brightest planet in sky 60+ moons Strong magnetic field Giant red spot Has small Rings

17. Saturn 6 th planet from sun Beautiful set of rings 31 moons Largest moon, Titan, Easily visible in the night sky Voyager explored Saturn and its rings.

18. Uranus 7 th planet from sun Has a faint ring system 27 known moons Covered with clouds Uranus sits on its side with the north and south poles sticking out the sides.

19. Neptune 8 th planet from sun Discovered through math 7 known moons Triton largest moon Great Dark Spot thought to be a hole, similar to the hole in the ozone layer on Earth

20. Outermost Planet Pluto, the outermost planet, is a small solid icy planet is smaller than the Earth's Moon. There is much debate to its being considered a planet and today it is considered a dwarf planet.

21. Pluto 9 th planet from sun (usually) Never visited by spacecraft Orbits very slowly Moon, Charon, is very close to Pluto and about the same size

22. Explore the Universe and expand your mind Susan Hammond TTl June 2003