Composite image of spiral galaxy M106

The name "telescope" covers a wide range of instruments and is difficult to define. They all have the attribute of collecting electromagnetic radiation so it can be studied or analyzed in some manner.

Types of telescopes

Optical telescopes

Radio telescopes

X-ray and gamma-ray telescopes


Image: Composite image of spiral galaxy M106 (NGC 4258), optical data from the Digitized Sky Survey is shown as yellow, radio data from the Very Large Array appears as purple, X-ray data from Chandra is coded blue, and infrared data from the Spitzer Space Telescope appears red. Two anomalous arms, which aren't visible at optical wavelengths, appear as purple and blue emission. Image credit: NASA/CXC/Univ. of Maryland/A.S. Wilson et al.; Optical: Pal.Obs. DSS; IR: NASA/JPL-Caltech; VLA: NRAO/AUI/NSF


NASA's Great Observatories

Chandra X-ray Observatory

The Chandra X-ray Observatory
Credit: NASA

To grasp the wonders of the cosmos, and understand its infinite variety and splendor, we must collect and analyze radiation emitted by phenomena throughout the entire electromagnetic (EM) spectrum. Towards that end, NASA proposed the concept of Great Observatories, a series of four space-borne observatories designed to conduct astronomical studies over many different wavelengths (visible, gamma rays, X-rays, and infrared). An important aspect of the Great Observatory program was to overlap the operations phases of the missions to enable astronomers to make contemporaneous observations of an object at different spectral wavelengths.

For more information about NASA's Great Observatories, visit these sites:

Hubble Space Telescope

Chandra X-ray Observatory



FFA Newsletter

A no-nonsense, no ads, weekly list of the best future technology articles worldwide.


Subscribe to the Newsletter