The solar system

Question 1

how many planets are there

Answer 1

eighth

Question 2

what are all the planets

Answer 2

Mercury
venus
earth
mars
Jupiter
Saturn
Uranus
Neptune

Question 3

what were the 2 ideas about the solar system

Answer 3

geocentric
heliocentric

Question 4

what was the geocentric model

Answer 4

stated that the earth was in the centre of the that that the moon and sun orbited around the earth

Question 5

what is the heliocentric model

Answer 5

that the sun is in the centre of the solar system and all the planets orbit around it

Question 6

what 5 things make the solar system

Answer 6

sun
planets
asteroids
comets
dwarf planets

Question 7

what are the 2 types of satellites

Answer 7

natural and artificial

Question 8

what are 2 examples of natural satellites

Answer 8

planets
mood

Question 9

what is a natural satellite

Answer 9

a satellite that is formed by natural processes

Question 10

what is an artificial satellite

Answer 10

manufactured on Earth and launched into orbit and space by rockets

Question 11

what are the 2 types of artificial satellites around earth

Answer 11

geostationary
low polar orbits

Question 12

what is a geostationary orbit satellite and what is its purpose

Answer 12

orbit around the equator of the earth and are used for GPS

Question 13

what is a low polar orbit satellite and what is its purpose

Answer 13

orbit close to the earth and are used for weather mentoring and spying

Question 14

why do comets have highly elliptical orbits

Answer 14

as they get closer to the sun the gravitational forces increase and weaken as you move away. this causes the comet to travel slower when far away from sun and faster when it is closer to it

Question 15

which planet has a higher orbital speed earth or Jupiter

Answer 15

earth

Question 16

what are the 2 theories about the universe

Answer 16

Big bang theory
Steady State

Question 17

what is the Big Bang theory

Answer 17

says that the whole universe started as a tiny particle that expanded from this point in space. and the universe is still expanding today

Question 18

what is the steady state theory

Answer 18

says that the universe has always existed and is expanding and new matter is being created as it expands

Question 19

what are 2 differences between steady state and Big Bang Theory

Answer 19

• big Bang says that the universe had a start while Steady State says that the universe has always existed
• in the Big Bang theory no new matter is created while the steady-state says that as the universe expands new matter is created

Question 20

what is a similarity between steady state and Big Bang Theory

Answer 20

both say that the universe is expanding

Question 21

what is evidence that the universe is expanding

Answer 21

red-shift

Question 22

what is evidence of big band theory

Answer 22

CMB

Question 23

what is Red-shift

Answer 23

when objects emit light such as galaxies are moving away from us then the light they emit is red-shifted. this is because the wavelengths detected on Earth will be stretched and will be turned towards the red end of the spectrum (longer wavelengths) as the object is moving away from us

Question 24

what does CMB stand for

Answer 24

Cosmic Microwave Background

Question 25

how does CMB support the Big Bang theory

Answer 25

it is said to be the echo of the Big band. at the time of the Big Bang, the radiation would have been extremely hot and intense over time the radiation has cooled and is now weak. the fact that this radiation is detected in all directions and has the temperature that it does shows that the universe started 14 billion years ago

Question 26

how long ago was the universe created

Answer 26

14 billion years ago

Question 27

what is the Doppler effect and how does it occur

Answer 27

the change in pitch of sound due to the movement of the sound source. when a sound source is moving towards you the sound waves get compressed making the frequency higher so the pitch sounds higher. however, if the sound source is moving away from you the sound wave is stretched out which lowers the frequency and causes the sound to sound lower

Question 28

what are the 2 types of stars

Answer 28

low mass
high mass

Question 29

what are the steps of the lifecycle of a low-mass star

Answer 29

• a nebula is pulled inward by the force of gravity as the dust contracts and the nebular gets hotter since work is being done on it
• eventually the dust and gas become hot enough for hydrogen nuclei to fuse via nuclear fusion into helium nuclei. the release of energy will release light this is a main sequence star
• when most of the hydrogen has been converted to helium the star will become hotter and will become a red giant to fuse the nuclei of heavier elements
• eventually, nuclear fusion stops due to elements being used up and the star collapses to become a white dwarf

Question 30

what is a nebula

Answer 30

a cloud of dust and hydrogen gas

Question 31

what is the difference between the life cycle of a high mass star and a low-mass star

Answer 31

a high mass star will form a super red giant and will explode in a supernova, if what remains after the explosion is less than 4 times the mass of the sun. gravity will pull it together to form a high-density neutron star. however, if there is more mass it will form a black hole

Question 32

what is a main sequence star

Answer 32

a star that uses the nuclear fusion of hydrogen to release energy and light

Question 33

why is it better to send telescopes to space (2 benefits)

Answer 33

as there is no atmosphere to blur the image
some parts of the EM spectrum are absorbed by the atmosphere

Question 34

what are 4 developments in telescopes and the effect that it has on the observation of the universe

Answer 34

• greater magnification - we can observe galaxies that are far away
• recording with cameras - we can gather more data
• can be made with greater precision - cleared images
• can detect other parts of the EM spectrum - we can observe objects that emit other EM waves