Lecture 7

Question 1

nebular theory

Answer 1

giant interstellar cloud (solar nebula) undergoes gravitational collapse formed everything

Question 2

close encounter theory

Answer 2

sun had a near-miss with another star and ejected debris that became other planets
-doesn’t explain orbital motion so it is wrong

Question 3

galatic recycling

Answer 3

system is formed from older dead stars

Question 4

Planetary creation

Answer 4

cloud collapses: gravitational energy is turned into heat

Question 5

frost line

Answer 5

-inside of the frost line hydrogen will not turn to gas

Question 6

planetary creation: terrestrials

Answer 6

planets collect as gravity attracts mass

Question 7

creation of Jovian

Answer 7

post frost line

-gravity collects planetesimals as they collide

Question 8

planetary creation summary

Answer 8

• gravitational collapse heats up nebula
• rock/metals condensed close to the sun
• rock/metals/ice condense further from sun

Question 9

Bombardment

Answer 9

• ice bodies collided with inner planets and created water

- sometimes capture occurred (mars moon)

Question 10

magnetics fields

Answer 10

-a result of accelerating charged particles 
three requirements 
-molten interior 
-convection 
-moderately fast rotation

Question 11

surface processes

Answer 11

impacts: craters from asteroid and comets
volcanism: eruption of molten rock onto surfaces
erosion: