1. THE SOLAR SYSTEM

2. The solar system Formed 4.6 billion years ago from a nebula a cloud of dust and gas The hot center from this nebula, shrinking and spinning, formed the sun Left over dust and gas formed planets around the sun

3. THE SUN – Hot ball of gas or a big star – It’s gravity holds objects together in the solar system Stops planets from flying off into space, keeps them in line of orbit

4. THE SUN Diameter = 1.4 km 27 million degrees Fahrenheit Large enough to hold 1 million Earth’s More information is in your textbooks on page D40

5. PLANETS: Large, round bodies that revolve around a star

6. Terrestrial Planets made mostly of rock Mercury Venus Earth Mars

7. Jovian Planets a gas giant planet does not consist of solid or rock Jupiter Saturn Uranus Neptune

8. Order of the Planets M yMercury V eryVenus E nergeticEarth M otherMars J ustJupiter S ervedSaturn U sUranus N oodlesNeptune Can you think of your own?

9. PLUTO?? In the Kuiper Belt made mostly of ice and rock Too small to be a planet, but known as a dwarf planet massive and has own gravity has not cleared the neighborhood around its orbit

10. STARS Massive balls of plasma Constellation: formation of stars Nearest star to Earth – Sun Most stars 1 – 10 billion years old

11. ASTEROIDS Rocky objects between Mars and Jupiter Too small to be a planet – hypothesis that failed to be a planet Giant chunks of rock that look like giant potatoes in space Some are the size of planets, others are the size of a basketball

12. COMETS Ice chunks that spin close to the sun Glowing clouds surround most comets, and tails of gas can often be seen trailing them as their orbits take them near the sun

13. GALAXIES Billions of stars together Stars, gas, dust, and dark matter