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Which galaxy contains the Solar System?
- The Milky Way
What is a galaxy?
A collection of stars
What name do we give to the thing that contains all the galaxies?
Put these objects in ascending order, Earth, moon, Sun, Jupiter, Universe, galaxies
What is a space probe?
- An unmanned space craft sent into space to gather information from places too far away or too dangerous to send manned craft.
What is SETI ?
The Search for Extraterrestrial Intelligence projects (SETI) analyse radio waves coming from space looking for signals that may have been produced by intelligent life
Why do space probes and landers all look for evidence of water (either currently on a planet or in its past)
All life as we know it depends upon liquid water
What do planetary landers (like those on Mars) do?
- Take photographs
- analyse soil samples
- take samples from the atmosphere
- explore the surface of the planet.
These activities are all aimed at looking for signs of life or for conditions that could support life.
List some ways that modern telescopes enable us to know more about the Universe than those used by Galileo.
- Improved magnification enables the observation of distant galaxies.
- Using radiation other than visible light enables other objects to be detected.
- We can use computers to analyse the large amount of data collected.
Why are some telescopes located outside the Earths atmosphere?
- The Earths atmosphere absorbs many types of radiation (eg x-rays and gamma rays).
- To receive these a telescope needs to be put outside the atmosphere.
What is a nebula?
- A cloud of gas and dust where stars are created.
What force pulls together the gas and dust in a nebula?
What is the main sequence stage of a star?
- It is the stable stage where stars spend most of their time.
- During this stage nuclear fusion is taking place.
- The forces of fusion and gravity are balanced so the star does not explode or implode (collapse)
What is a white dwarf
- The remnants of a star (of similar mass to the Sun).
- All its fuel has been used up and it has gone through the red-giant phase.
Put these stages of a stars lifecycle into the correct order. White dwarf, nebula, main sequence star, red giant
- main sequence star
- red giant
- white dwarf
(Higher) Stars more massive than our Sun have a different lifecycle to less massive stars. In what ways is the lifecycle different?
- Super red giants are formed rather than red giants.
- These then explode in a supernova which either results in a neutron star or for the really massive stars, a black hole.
Name the two theories about how the Universe was created.
What is the evidence for the Universe expanding?
- Light from distant stars is shifted towards the red end of the spectrum.
- This shows that they are moving away from us.
What is Cosmic Microwave Background (CMB) radiation and which theory about the creation of the Universe does it support?
- It is microwave radiation all around in space.
- It supports the Big Bang theory which predicted its existence.
What is the main difference between the Steady State and the Big Bang theory?
- The Big bang theory says that all matter in the Universe existed at the start and was originally contained in a tiny point of concentrated energy.
- The Steady State theory says that matter is constantly being created.
How old does the Big Bang theory suggest the Universe is?
13.5 billion years
How old does the Steady State theory suggest the Universe is?
It says that the Universe has always existed
(Higher) How does the amount of red-shift change as we observe more distance galaxies?
- The further away the galaxy the more red-shift.
- This shows that distance galaxies are moving away from us faster than nearer galaxies.
What name do we give to the phenomenon whereby light from a source moving away from us appears to have a lower frequency and longer wavelength than it really does?
Which theory about the creation of the Universe does red-shift support?
Both the Steady State and the Big Bang theories as both say that the Universe is expanding
Which is the currently accepted theory about the creation of the Universe?
- The Big Bang theory.
- It is the only theory that matches all the available evidence. (eg CMB radiation)