Radio Telescope Facts

  • Radio telescopes are telescopes that pick up radio waves instead of light waves.
  • Radio telescopes, like reflecting telescopes, have a big dish to collect and focus data.
  • At the center of its dish, a radio telescope has an antenna which picks up radio signals.
  • Because radio waves are much longer than light waves, radio telescope dishes are very big – often as much as 100 m across.
  • Instead of one big dish, some radio telescopes use an array (collection) of small, linked dishes. The further apart the dishes are, the sharper the image.
  • The Very Long Baseline Array (VLBA) is made of ten dishes scattered all the way across the USA.
  • Radio astronomy led to the discovery of pulsars and background radiation from the Big Bang.
  • Radio galaxies are very distant and only faintly visible (if at all), but they can be detected because they give out radio waves.
  • Radio astronomy proved that the Milky Way is a disc-shaped galaxy with spiraling arms.