Space Physics: Signals from Space

  1. the universe ...
    consists of many galaxies separated by empty space
  2. a galaxy is ...
    a large cluster of stars
  3. a star is ...
    • a large ball of matter that is undergoing nuclear fusion and emitting light and other forms of electromagnic radiation.
    • the sun is a star
  4. the sun ...
    has a solar system
  5. a solar system ...
    consists of a central star orbited by plants
  6. a planet is ...
    • a large ball of matter that orbits a star.
    • plants do not emit light themselves
  7. a moon is ...
    • a natural satellite
    • a lump of matter that orbits a plant
  8. why do we use the light year as the unit of distance in space?
    distances in space are so enormous, so its more appropriate
  9. what is a light year?
    one light year is the equivalent distance light travels in one year
  10. apart from the Sun what is the nearest star to Earth? how far away is it?
    • Proxima Centauri
    • 4.2 light years
  11. how long does light from our Sun take to reach us?
    8 minutes
  12. white light is made up of a range of colours. how can these colours be seperated?
    by splitting white light with a prism to obtain a spectrum
  13. what is a spectroscope?
    a spectroscope uses a prism to display the colours which make up a source of light
  14. what do optical telescopes do?
    observe visible light from space
  15. what are the disadvantages of optical telescopes on the ground?
    • they can only be used at night
    • they cannot be used if the weather is poor or cloudy
  16. what do radio telescpoes detect?
    radio waves coming from space
  17. what advantages do radio telescopes have over optical telescopes?
    • can be used in bad weather
    • can be used in daytime as well as night
  18. why do x-ray telescopes need to be at a high altitude?
    x-rays are partly blocked by the Earth's atmosphere
  19. what electromagnetic radiation is emitted through objects in the universe?
    • infrared
    • x-rays
    • gamma rays
  20. electromagnetic radiations are blocked by the Earth's atmosphere, what are they detected by?
    telescopes which orbit round the Earth
  21. Telescopes in space can ...
    observe the whole sky and they can operate both night and day.
  22. what are the disadvantages of telescopes in space?
    • they are difficult and expensive to launch and maintain.
    • if anything going wrong only astronauts can fix them
Card Set
Space Physics: Signals from Space
Space Physics: Section 1- Signals from Space