The Space observatory reference article from the English Wikipedia on 24-Jul-2004
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Space observatory

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A space observatory is any object in outer space which is used for observation of distant planets, galaxies, and other outer space objects. A large number of observatories have been launched into orbit, and most of them have greatly enhanced our knowledge of the cosmos. Performing astronomy from the Earth's surface is limited by the filtering and distortion of electromagnetic radiation due to the Earth's atmosphere. This makes it desirable to place astrononomical observation devices into space. As a telescope orbits the Earth outside the atmosphere it is neither subject to twinkling (distortion due to thermal turbulences of the air) nor to light pollution from artificial light sources on the Earth. Some terrestrial telescopes (such as the Very Large Telescope) can counter turbulences with the help of its novel adaptive optics.

But space-based astronomy is even more important for frequency ranges which are outside of the optic window and the radio window, as the two only wavelength ranges of the electromagnetic spectrum are called, that are not severely attenuated by the atmosphere. For example, X-ray astronomy is nearly impossible when done from the Earth, and has reached its current important stand within astronomy only due to orbiting satellites with X-ray telescopes such as the Chandra observatory. Infrared and ultraviolet are also greatly blocked.

Space observatories can generally be divided into two classes: missions which map the entire sky (surveys), and observatories which make observations of chosen parts of the sky.

Many space observatories have already completed their missions, while others are still operating. Satellites has been lauched by NASA, ESA and Japan space agency.

Table of contents
1 NASA's Great Observatories
2 Other notable space observatories
3 See also

NASA's Great Observatories

Satellites belonging to NASA's "Great Observatories" program:

Other notable space observatories

See also