In this image, several radio telescopes observe the Cosmos and capture the radio waves that reach our atmosphere from space. The amateur astronomer can make his observations with the naked eye, with binoculars or telescope.
Astronomical observations are our tool to know the Universe. What they study is the electromagnetic radiation emitted by celestial objects and travels through space. Visible light, which the human eye is able to perceive, is only a small part of that radiation. Each observation instrument specializes in capturing a different type of radiation.
On Earth, astronomical observatories with optical telescopes remain the most numerous. They capture visible light, that is, images. Some may also capture part of infrared radiation, which is received as heat.
Radio telescopes capture radio waves and convert them into electronic signals. Pulsars and quasars were discovered by this system. They are also useful for observing distant galaxies, since they are very visually weak, but emit large amounts of radiation in the form of radio waves.
Space telescopes capture radiation that does not pass through the atmosphere, such as X-ray waves (Chandra telescope) or gamma-ray waves (Compton telescope). The best known space telescope is the Hubble.
|◄ Previous||Next ►|
|Starry sky||Paranal Hill|