Space

Question 1

List the life cycle of a star the same size as the sun

Answer 1

Nebula
Protostar
Main sequence star
Red giant
White dwarf
Black dwarf

Question 2

List the life cycle of a star much bigger than the sun

Answer 2

Nebula
Protostar
Main sequence star
Red super giant
Supernova
Neutron star or black hole

Question 3

Explain how a nebula becomes protostar

Answer 3

A nebula is clouds of dust and gas.

The force of gravity pulls them together to form a protostar

Question 4

Explain how a protostar becomes a main sequence star

Answer 4

As the star gets denser, temperature rises and particles collide with eachother more. When the temperature is high enough, the star undergoes nuclear fusion, where hydrogen nuclei fuse to form helium nuclei. This gives our a lot of energy and makes the star form

Question 5

Explain a main sequence star

Answer 5

The longest stage or a star where it is stable from the outwards pressure and onwards gravity balance eachother. The star continues to undergo nuclear fusion.

Question 6

How does a main sequence star become a red giant or red super giant?

Answer 6

Eventually the hydrogen runs out so the star swells (as there is no longer as much outwards pressure which was caused from nuclear fusion). This swelling forms a red giant or if it is even bigger a red super giant. Fusion of helium and other elements occurs to make heavier elements up to iron.

Question 7

What is a white dwarf?

Answer 7

a hot, dense, solid core left behind when a small/median sized star becomes unstable so sheds its outer layers after being a red giant

Question 8

How does a red giant become a white dwarf?

Answer 8

The red giant becomes unstable so sheds out its outer layers of dust and gas to leave behind a white dwarf

Question 9

How does a white dwarf become a black dwarf?

Answer 9

The white dwarf cools down, so that it emits less energy. When it can no longer emit a significant amount, it is known as a black dwarf.

Question 10

What happens in a super red giant?

Answer 10

undergo lots of nuclear fusion, forming elements as heavy as iron
expand and contract several times

Question 11

What is a supernova?

Answer 11

an explosion (of a super red giant)
elements heavier than iron are formed from fusion, which are ejected into the universe to form new planets and stars

Question 12

What is left behind after a supernova explosion?

Answer 12

a neutron star or a black hole

Question 13

What is a neutron star?

Answer 13

a very dense core (left behind after the outer layers of dust and gas are thrown into the universe by a supernova)

Question 14

What is a black hole?

Answer 14

an infinitely dense point in space (formed from a supernova if the star is massive enough)

Question 15

What are the planets in our solar system?

in order of distance from sun

Answer 15

Mercury
Venus
Earth
Mars
Jupiter
Saturn
Uranus
Neptune

Question 16

What are planets?

Answer 16

large objects that orbit a star that are large enough to have cleared their orbits (their gravity is strong enough to have pulled in any nearby objects)

Question 17

What are moons?

Answer 17

a type of natural satellite that orbit planets

Question 18

What is a satellite?

Answer 18

an object that orbits a more massive object

Question 19

What are artificial satellites?

Answer 19

satellites that humans have built

Question 20

What are orbits?

Answer 20

the paths objects take as they more around another object in space

Question 21

What provides the force to create orbits?

Answer 21

gravity

Question 22

How does a satellite stay in orbit around a circle?

Answer 22

to be travelling in a circle, its direction much be constantly changing, meaning it us constantly accelerating
the object is constantly changing velocity (but not speed)
for an object to accelerate, there must be a force acting on it coming from the middle of the circle (this force is gravity)
this force would cause the object to fall towards the object it’s orbiting but because the object is already moving, the force causes it to change direction

Question 23

What does the size of an orbit depend on?

Answer 23

its speed

the stronger the force, the faster the orbit needs to travel in order to remain in orbit

Question 24

What is red-shift?

Answer 24

The idea that there is an observed increase in the wavelength of light from most distant galaxies. The further away the galaxies, the faster they are moving and the bigger the observed increase in wavelength.
This means that the universe is expanding as everything is gradually moving away from eachother.

Question 25

What is the Big Bang Theory?

Answer 25

the theory that initially all matter in the universe started from a very small point (which was hot and dense)
this point started expanding and has continued expanding since

Question 26

Name two examples of things scientists still know very little about in space

Answer 26

dark matter/mass

dark energy

Question 27

What should be done to theories when new evidence is found?

Answer 27

test them and if the new evidence doesn’t fit it, either the theory needs to be changed or they need to create a new theory