Bibliography

"Reflecting Telescope." Wikipedia. 21 November 2006. Wikipedia. 21 November 2006 <http://en.wikipedia.org/wiki/Reflecting_telescope>

"Reflecting Telescopes." All About Telescopes. 21 November 2006. All About Telescopes. 21 November 2006 <http://www.indepthinfo.com/telescopes/reflecting-telescopes.shtml>

"Reflecting Telescope." Reflecting Telescope. 21 November 2006. Reflecting Telescope. 21 November 2006 <http://abyss.uoregon.edu/~js/glossary/reflecting_telescope.html>

Nardo, Don. Telescopes. San Diego, Calif. : KidHaven Press, 2005.

The Conclusion

There are many different sorts of telescopes in the world and are all used for different things. Reflecting telescopes are used for observing objects in space. Did you know the Hubble Space Telescope is a reflecting telescope?

Many reflecting telescopes take after the Cassegrain Telescope, and are based off it. An ordinary Newtonian telescope has a basic primary mirror, a secondary mirror, tubes, eyepieces, and focal planes. Light bounces off the primary mirror, onto the secondary, and sends it to focal planes with eventually lead to the tube and eyepieces, where you see the image. A telescope is a cool invention, and without it, we wouldn't even know planets and stars existed!

The Main Ideas : The Creators

The first one to have made a reflector was an Italian monk, named Niccolo Zucchi, during the 1616's. But the reflector he had made had flaws, and he gave up the project. His concave mirror was of the wrong shape, and he couldn't view the images without blocking the mirror. About 54 years later, his invention was refined at the hands of Sir Isaac Newton, the same one who had discovered gravity. He fixed the monk's flaws, and the traditional two-mirrored reflecting telescope was named after him, called the Newtonian reflector.

The Main Ideas : The Types Of Reflecting Telescopes

The Cassegrain telescope has a parabolic primary mirror and a hyperbolic secondary mirror that reflects the light through the hole in the primary mirror. This kind of telescope is designed to be small and and simple, and protects the parts inside the telescope. The image to the right shows how the Cassegrain telescope works. The Ritchey-Chrétien, Dall-Kirkham, and Schiefspiegler are all reflected telescopes based off of the Cassegrain.





The Gregorian Telescope has a concave secondary mirror instead of a convex. This type of telescope is useful for land observations, and it isn't very common anymore. The image on the left shows how the Gregorian Telescope works.


Nasmyth reflectors are similar to the Cassegrain reflectors. However, the Nasmyth telescopes don't have the extra hole in the primary mirror, but a third mirror that makes the light bounce off to the side.

The Main Ideas : The Telescope And How It Works

The reflecting telescope; from its name, you can easily deduct that this telescope gathers light and reflects it to form an image. This type of telescope uses a mix of curved and flat mirrors.

There are a few parts to the reflecting telescope, the main part being the curved primary mirror that creates the image at the focal plane (Where the image is focused). The focal length is the distance between the mirror and the focal plane. Along the focal length, film and digital sensors could be placed to record the images or an eyepiece to view the images. There is also the secondary mirror, which is placed diagonally and it reflects the light to the focal plane at the side of the telescope tube, another part that's placed under the eyepiece. These are the main parts of the common Newtonian reflector. Other types of reflecting telescopes include the Cassegrain, Nasmyth, Coudé, and Gregorian.

The light reflects off the primary mirror, then focuses on the secondary mirror which in turn sends it to the focal plane. This is how the reflecting telescope works.

Intro : My Topic

What's the invention you use to see and observe far away and sometimes into space? If you guessed the telescope, you're right. I chose this topic because I've adored the idea of having a telescope on the balcony in the attic, observing the planets and stars at night. It seems a very fun and relaxing idea to me, and so I chose telescopes to research and learn about. They are usually used for observing things in space, things related to astronomy. One of the more famous telescopes is the 'Hubble Space Telescope'. It orbits in space around Earth, and observes objects in space, such as planets and stars.

There are different types of telescopes, with optical telescopes being the most common. Refracting, reflecting, catadioptric telescopes are all optical telescopes. Refracting telescopes, obviously, refracts light on lenses inside the telescope and forms an image. Catadioptric telescopes use an assortment of lenses and mirrors to refract and reflect to form pictures. The type of telescope I'm researching is the reflecting telescope.