P1 - Foundation Part 3 – Space Put these in order of smallest to largest. Star, Galaxy, Solar system, Moon, Universe, Planet.

Moon Planet Star (sun) Solar system Galaxy Universe

The Solar System is about 4,600 million years old. It was formed from a nebula – an enormous cloud of dust and gas. Over millions of years, gravity pulled the dust and gas together, the temperature rose and pressure increased. Eventually, the core started fusion and became the Sun. How was a star formed?

What you need to know. Stars about the same size as our Sun These follow the left hand path: Main sequence star → red giant → white dwarf → black dwarf Stars much bigger than our Sun These follow the right hand path: Main sequence star → red super giant → supernova → neutron star or black hole

(i) State what a nebula is. (1) (ii) A nebula eventually becomes a star. Describe how a nebula becomes a star. (3) (b) These are four stages in the evolution of a star similar to the Sun. They are not in the correct order. 1. main sequence star 2. white dwarf 3. red giant 4. nebula Write down the stages in the correct order. (2) The first stage has been done for you nebula How you will be tested.

(cloud of) dust and/or gases (1) Accept hydrogen/helium Accept idea that it is where stars/planets are formed Ignore rocks/smoke (1) AnswerAcceptable answers Mark A description linking three of the following when nebula reaches a critical mass (1) nebula collapses/contracts (1) (due to) gravitational attraction (1) (gets) hot/ (makes) heat (1) forms a protostar (1) emits/produces light /radiation(1) correct sequence is not required when nebula or dust/gas cloud is big (enough) gases/dust/nebula come together/pulled together/spiral /move faster gravity/gravitational (potential) energy transformed into thermal energy ignore starts to burn/explodes/friction starts nuclear reaction/fusion/ hydrogen turns into helium/new elements (3)

(nebula) main sequence (star) (1) AND red giant white dwarf (1) All three in correct order for 2 marks Red Giant White Dwarf (Main sequence) (1)

The Big Bang theory The theory states that about 13.7 billion years ago all the matter in the Universe began to enlarge rapidly in a hot explosion, and it is still expanding today. Evidence for the Big Bang includes: all the galaxies are moving away from us (red shift) the further away a galaxy is, the faster it is moving away. (red shift) Scientists have also detected a cosmic microwave background radiation or CMBR. This is received from all parts of the Universe and is thought to be the heat left over from the original explosion.

Steady state The Steady State Theory suggests that as the universe expands new matter is created, so that the overall appearance of the universe never changes. There is no start or end in this theory. Supported by red shift but NOT by CMBR.

Hubble's work led to the theory of the Big Bang. Describe what is meant by the Big Bang theory. (2) There are two theories for the origin of the Universe: the Big Bang Theory the Steady State Theory. (i) Describe the evidence which supports the Big Bang Theory. (2) (ii) The Steady State Theory is not as widely accepted as the Big Bang Theory. Suggest a reason for this. (1) How you will be tested on this.

A description including the following points in a logical order EITHER red shift (1) detail of red shift (1) OR cosmic microwave background (CMB) (1) detail of CMB (1) Accept d galaxies are moving away correct wavelength / frequency change echo of the Big Bang uniform in all directions correct reference to temperature of space AnswerAcceptable answers more evidence for the big bang theory / converse evidence for the big bang theory is more reliable / repeatable / eq CMB does not support Steady State

Galileo Galilei ( ) was an Italian astronomer working at a time when all Scientists believed the earth was the centre of the Universe and all planets orbited it (the geocentric model). Using the newly invented telescope he discovered that Jupiter had four moons. As these moons were orbiting Jupiter itself, this showed that not everything orbited the Earth.

Heliocentric theory put the sun at the centre if the universe. We all see the sun and moon moving across the sky and both the theories explain this. Only Heliocentric explains Jupiter's moons and why the planets move from East to West (retrograde) unlike the Sun which goes West to East.

A long time ago, astronomers thought that the Earth was the centre of the Universe. This was called the geocentric model. The evidence for this model came from observations of the sky using the naked eye. After the telescope was invented, astronomers quickly gathered evidence which showed that the geocentric model is not correct. Describe the evidence both for the geocentric model and against the geocentric model. (6) How you will be tested.

Telescopes Telescopes are devices used to observe the universe. There are many different types and some are even sited in space. Optical telescopes Optical telescopes observe visible light from space. Optical telescopes on the ground have some disadvantages: they can only be used at night they cannot be used if the weather is poor or cloudy Other telescopes Radio telescopes detect radio waves coming from space. They can be used in bad weather because the radio waves are not blocked by clouds as they pass through the atmosphere. Radio telescopes can also be used in the daytime as well as at night.

Telescopes in space Telescopes in space can observe the whole sky and can operate both night and day. Above clouds so can’t be blocked by them. No atmosphere bending light/blurring image. No light pollution (unless it’s the sun). They are difficult and expensive to launch and maintain. If anything goes wrong, only astronauts can fix them. Objects in the universe emit other electromagnetic radiation such as infrared, X-rays and gamma rays. These are all blocked by the Earth's atmosphere, but can be detected by telescopes placed in orbit round the Earth.

How you will be tested. Describe a benefit of using a telescope in space. (2) Galileo’s telescope used a small lens to focus the light. Modern telescopes often use a large mirror instead. Explain how using a modern telescope helps astronomers to understand the Universe better. (3)

A description including any two of the following above the/no atmosphere (1) above the clouds / no clouds/no weather (1) image is clearer/ more detailed/ not distorted/not blurred (1) no light pollution (1) no absorption (by atmosphere) of other named radiations e.g. Xrays (1) no air/dust/pollution can see further /wider field of view/can use anytime IGNORE it is closer (to the stars/planets) IGNORE references to improving understanding / knowledge of space

An explanation to include the following points in a logical order EITHER idea of more {data / light} (captured) (1) so can see dimmer objects (1) so can identify {smaller / more distant} objects (1) OR idea of more magnification (1) so can see more detail (1) so can identify {smaller objects}(1) image looks brighter image looks bigger more distant objects