1. Question of the Day: – Why is it important we know about space and our galaxy? Objective: I can explain the nebular theory. Honors HW: Work on your check off sheet vocab. Turn in all missing assignments so you can go to reward day May 11!!!!!

2. Solar System Questions… What makes up our solar system? Can you name the planets? Can you order them, closest to farthest from the Sun? What percent of the solar system’s mass is the planets? A. 50%C..15% B. 99.85%D. 80%

3. Solar System Answers… The sun and a huge rotating system of planets, their satellites, an numerous smaller bodies Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune 99.85% of the mass of our solar system is contained within the sun. The planets collectively make up most of the remaining 0.15%.

4. Inner Planets vs. Outer Planets Terrestrial planets: Mercury, Venus, Earth, Mars Relatively small, rocky & metallic More dense (5x water) Closer to sun, warmer Thin atmosphere Weaker surface gravity Lower escape v ~11km/s Jovian planets: Jupiter, Saturn, Uranus, Neptune Giants, made of gas & ice w/rocky, metallic cores Less dense (1.5 x water) Farther from sun, colder Thick atmosphere Greater surface gravity Higher escape v 21-60 km/s

5. Planets Drawn to Scale

6. The Nebular Theory How did our Solar System form?

7. Gravity Gravity – what is it? - attractive force brining items towards itself Bigger or smaller equal more gravity? - _________ objects have more gravity - Earth much more gravity than humans

8. Inertia Inertia – What is it? - An object in motion will stay in motion; an object at rest will stay at rest… More dense or less dense spin faster? - _____ dense - ANALOGY: Think about a figure skater, spins faster when brings arms towards body

9. Terrestrial vs. Jovian Formation of the Solar System Nebular Theory: the sun and planets formed from a rotating disk of dust and gases (a nebula). Nebula/Interstellar cloud – large cloud of interstellar gas (mostly hydrogen and helium) and dust that collapses on itself, due to its own gravity, and forms a hot, condensed object that will become a new star

10. 1. Nebula

11. 2. Nebula Spins

12. 3. Sun Forms

13. 4. Planetesimals Form

14. 5. Planets Form

15. Review: Put into order ___ Nebula Spins ___ Sun forms ___ Planets form ___ Nebula ___ Planetesimals form

16. Review: Put into order _2__ Nebula Spins _3__ Sun forms _5__ Planets form _1__ Nebula _4__ Planetesimals form

17. a.Nebula b.Nebula spins b.Sun forms d.Planetesimals form e.Planets form

18. Compare and contrast the composition of the inner and outer planets. Why is this?

19. Planet Formation Temperatures Plot Does this help?

20. Our Solar System 99.85% of the mass of the solar system is in the sun. Sun: 1.9882 x 10^30 kg Earth: 5.9742 X 10^24 kg *REMEMBER: every power is ten times bigger