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The solar System
1. Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune.
2. Planets reflect sunlight and orbit the sun in ellipses.
3. A galaxy is a collection of stars.
  1. We live in the Milky way galaxy.
4. One light year = 9.5x10 to the 12 km
Is anyone out there?
1. SETI
  1. Search for extraterrestrial intelligence
  2. Looking for narrow bands of radio waves coming to earth in all the "noise"
    1. 'Noise' come from stars.
2. Robots and probes
  1. Collect data and samples
    1. Scientists still have to work out what it means.
Looking into space
1. 3 main problems telescopes face:
  1. Atmosphere absorbs a lot of light from distant planets
    1. Corrections put the telescope in space.
  2. Light pollution, light thrown up into the sky makes it hard to pick out dim objects
    1. Correction place on top of a mountain away from city light.
  3. Air pollution dust particles can absorb and reflect light.
    1. Correction place on top of a mountain less atmosphere above.
2. X-ray telescopes
  1. see violent high temperature events.
3. Radio telescope
  1. Discovered cosmic microwave background radiation.
Spectrometers
1. Used to analyse the light given out by a star.
2. The light spectra from stars contain bright lines and black lines
  1. Black line are where the the light at those wavelengths are being absorbed.
  2. Bright lines are extra light being emitted at those wavelengths.
3. Making a simple one: box a cd and light
Life cycle of a star
1. Nebula (dust and gas)-Main sequence star (the nebula spirals in together, temperature rises, hydrogen nuclei undos thermo nuclear fusion to form helium nuclei stable for several billions of years)-Red giant (Hydrogen running out the surface cools)
  1. Small
    1. Planetary Nebula (ejects outer layer)-White dwarf (solid dense core)
  2. Big
    1. Supernova (undergo more fusion creating heavier elements)-Neutron star (Very denser core or a black hole. (dense enough collapses in on its self)
Origins of the universe
1. Red shift
  1. When a source moves towards a person the observed wavelength decreases and the frequency increases. However if a object is moving away from the person the wavelength is higher and the frequency is lower. When you observe distant galaxys they tend to shift toward the red end meaning there moving.
2. Microwave background radiation
  1. Low frequency radiation
  2. As the universe expands and cools this background radiation "cools" and drops in frequency
3. Big bang theory matter compressed massive explosion. Creating a expansion which is still going on. 14 billion years ago.
4. Steady state theory says the universe has aways been around.

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	Erstellt von James Disley vor fast 10 Jahre