5. Nebular Theory

6. Nebula Cloud of dust and gas in space

7. Formation of our solar system: The nebular hypothesis (Kant, 1755)

9. Angular Momentum Conservation also explains why objects rotate faster as they shrink in radius:

12. Formation of our solar system: The nebular hypothesis (Kant, 1755)

13. Planetesimals

14. Formation of our solar system: The nebular hypothesis (Kant, 1755)

16. .2% 1,000 – 1,600 K Iron (Fe), Nickel (Ni), Aluminum (Al) Metals .4% 500 – 1300 K Various Rock 1.4% < 150 K Water (H20), Methane (CH4), Ammonia (NH3) Hydrogen Compounds 98% Do not condense in nebula Hydrogen (H), Helium (He) Hydrogen and Helium Gas Relative Abundance in Solar System Condensation Temperature Examples

18. Earth formation Nebula forms out of H, He clouds and fusion products from now dead stars. Gravity pulls gas and dust inward, and rotation makes a accretionary disk. The proto-sun is at the center and fusion begins when it is hot enough. Heavier elements concentrate in the inner rings. Collisions and gravitational attraction leads to the formation of planetesimals. Gravity reshapes the proto-Earth into a sphere Soon after Earth formed, a Mars-size planet collided with Earth, blasting debris into space that will form our Moon. Volcanic gases form the atmosphere, and as Earth cools, moisture condenses and rains into oceans. Some gases may have come from passing comets.

21. 2. List each planet and the main facts about each.

33. Kuiper Belt

36. List the terrestrial planets. Mercury Venus Earth Mars

37. What does the term, “terrestrial” mean? Earth-like

38. List the jovian planets. Jupiter Saturn Uranus Neptune

39. What does the term, “jovian” mean? Jupiter-like

40. What are the terrestrial planets made of? Rocky and metallic substances

41. What are the jovian planets made of? Hydrogen and Helium Gas H compunds (ex. Ammonia, Methane)

42. Planetesimals Small, irregular shaped bodies resulting from colliding bits of matter.

44. Asteroid Small rocky bodies

45. Comet Pieces of rocky and metallic materials

46. Coma The glowing head on a comet

47. Meteoroid A small solid particle traveling through space.

48. When is a meteoroid called a shooting star? When it enters the earth’s atmosphere.

49. Meteor A meteoroid that burns up in earth’s atmosphere.

50. Meteorite A meteoroid that reaches the earth’s surface.