Space

Question 1

What is the solar system?

Answer 1

The collection of 8 planets and their moons in orbit around the sun, with smaller bodies of asteroids, meteoroids and comets.

Question 2

Definition of a galaxy?

Answer 2

A system of millions or billions of stars, together with gas and dust, held together by gravitational attraction.

Question 3

What is the size of a:

Black hole

Answer 3

singularity in space, can be an atom - millions of km diameter

Question 4

How dense is a black hole?

Answer 4

Infinitely dense

Question 5

Why do we not know exactly what is in a black hole?

Answer 5

Because we cannot observe it as the gravitational field is so strong that light cannot escape.

Question 6

Planets in the solar system

Answer 6

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

Question 7

What is a neutron star?

Answer 7

When a red supergiant runs out of fuel, it relies on neutrons to stop it from collapsing. It is very heavy but very small and doesn’t happen all the time.

Question 8

What is a light year?

Answer 8

A light year is a measure of distance. It is the distance travelled by light in a year.

Question 9

Why can weight change depending on what planet you are?

Answer 9

Weight = mass X gravitational field strength.

The gravitational field strength will change if you change planets which would therefore affect the weight.

Question 10

Groups of planets in the solar system?

Answer 10

Gas giants(Jupiter to Neptune) and terrestrial planets (Mercury to Mars).

Question 11

Why do stars not collapse?

Answer 11

Stars do not collapse because they perform nuclear fusion to release a ton of energy. It is the only known place in the universe known to be able to perform nuclear fusion.

Question 12

What are:

Stars

Answer 12

A giant ball of burning gas, usually hydrogen, which performs nuclear fusion to release energy

Question 13

What is a:

Planet

Answer 13

A large lump of rock orbiting a star

Question 14

What is a:

Comet

Answer 14

Ice and dust, small, fast, has a very eccentric orbit

Question 15

What is an:

Asteroid

Answer 15

mostly rock, small, fast, very eccentric orbit

Question 16

What is a:

Moon

Answer 16

A body orbiting a planet called a natural sattelite

Question 17

What is a:

Centripetal force

Answer 17

• A force acting towards the circle/turn
• Required for a body to turn in a circle
• done by another real force, just a label

Question 18

What is the life cycle of a:

Small star

Answer 18

1. Nebula - dust and gas held by gravity
2. Proto Star - star beginning to form and rotates gaining energy as Nebula collapses
3. Main sequence - burns hydrogen - spends 90% of its life in this stage
4. Red Giant - only low mass stars reach this - burns helium and eventually other elements till iron
5. White Drawf - Not enough fuel to burn, so contracts itself into a white dwarf - which cannot collapse further due to electrons holding it together. Emmits light and some thermal energy
6. Black Dwarf - No more remaining light or energy

Question 19

What is the life cycle of a :

High mass star

Answer 19

1. Nebula - dust and gas held by gravity
2. Proto Star - star beginning to form and rotates gaining energy as Nebula collapses
3. Main sequence - burns hydrogen - spends 90% of its life in this stage
4. Red Supergiant - only high mass stars go here. Burns fuels up to (not including ) iron
5. Supernova - not enough fuel so a giant explosion happens where other elements are made
6. a - neutron star - all mass collapses into a small star around 20km wide, which is held by neutrons replling each other
7. b - Black hole - a singlularity where all mass collapses into a single point with infinite density and high enough gravitational field strenght that light cannot escape.