Why are orbiting telescopes important

Infrared observatories in space must be kept very cold because otherwise infrared radiation from the telescope itself would interfere with its ability to observe infrared radiation from space.

Spitzer exhausted its liquid helium coolant in and only a few of its instruments are still being used. Herschel's mission came to an end in , when it also ran out of coolant.

Astronomers study the infrared wavelengths to study the early universe and to learn about objects that are too cold to generate visible light including brown dwarf stars and dust clouds.

Visible wavelengths make it through Earth's atmosphere, but turbulence in the atmosphere causes images of stars to be blurred and spread out by at least 0. The Hubble Space Telescope observes from an orbit about km above the Earth at wavelengths from near infrared through the visible range and into the ultraviolet. It has a 2. It was put into orbit in and had a major repair in The JWST will be optimized for infrared observation, however, and ground based observatories will be the main source of observations in the visible range when Hubble is no longer able to operate.

It had a 1. The Hubble is the first telescope specifically designed to berepaired in space by astronauts, while other space telescopes cannot beserviced at all. NASA scientistsestimate that the telescope will only be able to keep taking pictures for fivemore years. Join our Space Forums to keep talking space on the latest missions, night sky and more!

And if you have a news tip, correction or comment, let us know at: community space. Remy Melina. They can be built bigger and for less money. Practically speaking, they also have a much lower risk of being damaged by one of the , pieces of debris flying through the cosmos—or space junk.

But increasingly, scientists and engineers are turning to space as the new frontier for advanced telescopes. When a telescope on the ground looks to the cosmos and takes a picture, the light it captures has first travelled through air in the atmosphere.

If that air is at all turbulent, it blurs the light. For some research projects, image quality is not all that important, but for researchers who need high-resolution photos to do their work, many ground-based telescopes present a problem.

In the decades that followed the giant-balloon strategy of the s, it became clear that what was really needed was free-flying space telescopes—that is, telescopes that can orbit on their own. The Great Observatories program led to the creation of four big, powerful space-based astronomical telescopes, including the Spitzer Space Telescope and the Hubble Space Telescope that launched over 25 years ago, in Space-based telescopes like Hubble get a much clearer view of the universe than most of their ground-based counterparts.