Unit 3.1-3.2

1. Unit 3.1-3.2 6th grade science

2. Vocabulary • Astronomical Unit (AU): the Earth’s average distance from the Sun (93,000,000 miles) • Ellipse: Flattened circle or oval. Most planets travel in an elliptical orbit. • Terrestrial planet: planets with rocky crusts and dense mantels and cores. • Tectonics: process of change in a crust due to the motion of hot material underneath • Volcanism: process in with molten (melted rock) moves from a planet’s hot interior onto its surface.

3. Formation of the Solar System

4. Thinking Questions • Why do you think that the outer planets are gas giants and the inner planets are made of heavy metals? • What was in our solar system before our Sun? How do we know this? • Why do you think that all the planets and the Sun orbit on the same elliptical plane?

6. Processes that shape a terrestial planet’s surface. • Tectonics- think earthquakes • Mantle Cycle • Volcanism- Process by which molten rock moves from the mantle to the surface • Weathering and Erosion- breaking down of material and transportation of this material. • Erosion and Weathering • Impact Cratering

8. Inner Planets Mercury, Venus, Earth, Mars With enough mass/gravity, all but Mercury were able to create atmospheres. Inner planets

9. Mercury • 6% of Earth’s Mass • 0.39 Au from Sun • Orbits “year” is 88 Earth days • No atmosphere • Rotates “day” is 59 Earth days

10. Venus • 82% of Earth’s mass • Diameter- 95% of Earth’s • Distance: 0.72 Au • “Year” is 225 Earth days • “Day” is 243 Earth days • Air pressure is 90 times Earth • Atmosphere is mainly CO2 • Clouds of sulfuric acid

11. Mars • 11% of Earth’s mass • Diameter is 53% of Earth • Distance is 1.5 AU • “Year” 1.9 Earth Years • “Day” is 25 Earth hours • Air pressure is1% of Earth and is mainly CO2 • Frozen water at poles. At one time had liquid water • Largest volcano is the solar system

12. Gas Giants • Made mainly of hydrogen, helium and gases • All have rings and various numbers of moons.

13. Jupiter • Mass: 318 Earth Masses • Diameter: 11 times Earth’s • Distance: 5.2 AU • “Year” : 12 Earth years • “Day” : 9.9 Earth hours • Great Red Spot has lasted hundreds of years.

14. Saturn • Mass: 95 Earth Masses • Diameter: 9 times Earth’s • Distance: 9.5 AU • “Year” : 29 Earth years • “Day” : 11 Earth hours • Known for its rings of frozen ice. • Has tilt like Earth except its season last 7 Earth years.

15. Uranus • Mass: 15 Earth Masses • Diameter: 4times Earth’s • Distance: 19 AU • “Year” : 84 Earth years • “Day” : 17 Earth hours • Axis of rotation is even with plane of revolution. • Methane gas gives it a bluish color.

16. Neptune • Mass: 17Earth Masses • Diameter: 4 times Earth’s • Distance: 30 AU • “Year” : 164 Earth years • “Day” : 16 Earth hours • Has a Great Dark Spot like Jupiter. • Methane gas gives it a bluish color

17. Pluto, the planet that was… • 2006 decided it was no longer a planet, but a dwarf planet. • Mass: 0.2% of Earth’s • Diameter: 18% of Earth’s • Distance: 40 AU • Orbits:248 Earth Years • Rotates: 6 Earth Years • Moon: Charon, but often referred to as a double planet.

18. Speaking of moons… • Many of the gas giants’ moons were larger than Pluto • Saturn and Jupiter have moons that have atmospheres, active volcanoes, active tectonics. • Some are small, even captured asteroids.

19. Asteroids • Small, rocky bodies that orbit close to Sun • Most orbit in the asteroid belt between Mars and Jupiter • Responsible for the mass extinction of the dinosaurs. • Dinosaurs Extinction 5 min

20. Comets • Often called “dirty snowball”, these objects produce comas from their icey cores. • Tails always point away from the Sun and get larger the closer they are to the Sun. • Comets 4 minutes

21. Meteors and Meteroites • Particles that hit the Earth’s atmosphere and often glow from the friction. • Meteorites actually reaches the surface. • If the Moon was replace by some of our planets