Chapter 8: Formation of the Solar System

Question 1

Why are there two major types of planets?

Answer 1

Close to the sun, only metals and rocks could condense into solid foundations for terrestrial planets. Further from the sun hydrogen compounds could condense as well as rock. Because of the abundance of hydrogen compounds in the solar nebula, this resulted in the formation of jovian planets.

Question 2

What percentage of the solar nebula was made up of hydrogen and helium gas?

Answer 2

98%

Question 3

What percentage of the solar nebula was made up of hydrogen compounds?

Answer 3

1.4%

Question 4

What percentage of the solar nebula was made up of rock?

Answer 4

0.4%

Question 5

What percentage of the solar nebula was made up of metal?

Answer 5

0.2%

Question 6

Describe the process of accretion.

Answer 6

• Microscopic particles condese from the solar nebula. These particles orbit the sun and attract other particles throught the electrostatic force
• As the combined mass of these particles increase, they begin to attract even more particles though gravity. They eventually increase in mass until they can be considered planetesimals.
• At first the planetesimals grow rapidly, as there are plenty of particles and other planetesimals to increase their mass
• Eventually, only the largest planetesmials survive, becoming full-fledged planets

Question 7

What is a planetesimal?

Answer 7

Small planet like boulder

Question 8

What cleared the solar nebula?

Answer 8

Solar wind from the young sun.

Question 9

What was the period known as the heavy bombardment?

Answer 9

The first few hundred million years of the solar system’s history in which every world in the solar system was pelted by impacts.

Question 10

What is the cause of our unusually large moon?

Answer 10

Giant impact theory states that the moon was likely a mars sized planetesmial that collided with earth. This planetesmial then remained in orbit around the earth.