Origin of the Solar System

Question 1

Nebula

Answer 1

• Irregularly shaped cloud of gas/dust (mainly gas)

- Light years in diameter, located within galaxies

Question 2

What gases are in a nebula?

Answer 2

• Mainly hydrogen and helium (lightest elements)

- Left over from big bang

Question 3

What is the dust in a nebula made out of?

Answer 3

• Microscopic particles of minerals, metal and ice
• Made of heavy elements (not hydrogen or helium) produced in the cores of stars and spread through space when supernova occurs

Question 4

What is the first step in creating a star?

Answer 4

A portion of a nebula needs to collapse assisted by a supernova

Question 5

How do planets form?

Answer 5

By the progressive collision of dust particles to form larger and larger objects

Question 6

How do planets form?

Answer 6

The progressive collision of dust particles to form larger and larger objects

Question 7

The solar system consists of (in order of importance):

Answer 7

1) the sun
2) the planets
3) astroids

Question 8

What is a planet?

Answer 8

• Orbits the sun
• Needs enough mass to be spherical
• Needs to have cleared out its orbit of other objects

Question 9

What are terrestrial planets?

Answer 9

• Composed of rock (silicate minerals/metal)
• Rocky crust/mantle
• Iron-nickel core

Question 10

What are gas giants?

Answer 10

• (Jovian Planets)
• Composed mainly of gases
• Rocky cores which resemble a terrestrial planet
• Dozens of moons
• Have rings

Question 11

What are asteroids?

Answer 11

Rocky objects orbiting primarily between Mars and Jupiter

Question 12

What are the main gases in the solar system (and in gas giants)?

Answer 12

• Hydrogen
• Helium
• Methane
• Ammonia

Question 13

What starts the process of a star forming?

Answer 13

A supernova

Question 14

How does a star form?

Answer 14

1) A nebula begins to collapse under its own gravity (temp increases)
2) It begins to rotate faster and faster (angular momentum)
3) It thins into a disk shape with most of its mass in the center
4) Interior begins to heat up (density increases), when temp in core = 10 million degrees, thermonuclear fusion begins (hydrogen converts to helium, releasing energy)

Question 15

Why are the outer planets gas and the inner planets rocky?

Answer 15

During the creation of the solar system, gas was pushed to the outer half of the solar system because it is lighter/ smaller than dust (outer half = gas, inner half = dust + gas)

Question 16

Why is this model so successful?

Answer 16

1) Explains why all planets orbit the sun in the same plane
2) Explains why planets (+asteroids, etc) revolve in the same direction
3) Explains the difference between the inner and outer planets