Stars and planets

Question 1

What makes up our solar system?

Answer 1

• 1 star (the sun)
• 8 planets
• 146 moons
• 5 dwarf planets
• an asteroid belt
• many comets

Question 2

What are the planets in order away from the sun?

Answer 2

Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.

Question 3

Acronym for the planets?

Answer 3

My very easy method just speeds up naming.

Question 4

The difference between outerplanets and innerplanets?

Answer 4

Rocky planets closer to the sun, gas giants after the asteroid belt.

Question 5

What are the gas giants mainly composed of?

Answer 5

Hydrogen, helium and some methane.

Question 6

What is earth radius?

Answer 6

The size of the planet measured relative to the Earth.

Question 7

What is an astronomical unit?

Answer 7

The average distance of the Earth from the sun.

Question 8

What is a light year?

Answer 8

Light years is the distance that light travels in 1 year and is equal to 9.47x10^15m.

Question 9

How did the solar system form?

Answer 9

• supernova explosion
• nebula
• nebula collapses in on itself, forming protostars.
• nuclear fusion starts after the core reaches 15 million degrees.

Question 10

What is a main sequence star?

Answer 10

One that releases energy by fusing hydrogen into helium.

Question 11

Explain the layout of the Hertzsprung Russel diagram.

Answer 11

Luminosity (light energy emitted by the star) on the y axis. The temperature (kelvin) runs along the x axis. The x axis can be displayed as colour. Red stars are the coolest and blue stars the hottest.

Question 12

What can be found in the top left of a HR diagram?

Answer 12

Hot, bright stars (largest main sequence stars)

Question 13

What can be found on the top right of a HR diagram?

Answer 13

Cool and bright stars (red supergiants)

Question 14

What can be found on the bottom right of a HR diagram?

Answer 14

Hot, dim stars (white dwarf stars)

Question 15

What can be found on the bottom left of a HR diagram?

Answer 15

Cool, dim stars (red dwarfs)

Question 16

What is the life cycle of a star like the sun?

Answer 16

Protostar
Main sequence (fusing hydrogen into helium)(equal forces)
red giant (hydrogen runs out, radiation force bigger, unbalanced so star expands)(undergoes nucleosynthesis to form heavier elements up to iron)
planetary nebula (fusion ceases)(outer atmosphere puffed but core becomes denser as the gravity force is greater)
white dwarf (gives out light because it is very hot)
red dwarf (continues to cool and become less luminous)
black dwarf (incredibly dense, cool and cannot be seen)

Question 17

What is the life cycle of a star bigger than the sun?

Answer 17

Main sequence
red supergiant (rapid collapse from massive gravity and no nucleosynthesis)
supernova explosion (energy released is so great that elements heavier than iron is formed)
Low mass - huge nebulae (rep cycle
High mass - neutron stars (very dense made out of neutrons)
Black holes (continues to collapse on its self until an infinintely small point)