Saturday, August 13, 2011

Types of Telescopes: Modern Versions

Telescopes have been around for hundreds of years and their birth is commonly associated with Galileo although in reality Hans Lippershey, Zacharias Janssen and Jacob Metius all laid claim to inventing earlier models. These "original" telescopes that were created are still mostly what people associate with when they think of telescopes but it is a universe away from what modern telescopes have evolved into.

This original telescope design is known as Refracting or Refractor telescopes and consist of a singular tube that light passes down in a straight line to the eyepiece. These types of telescopes are still around today but they have some limits in modern astronomy. They are rugged, great for lunar or planetary viewing and good in light polluted urban areas, but are limited when used for deep space viewing. Because the lenses are expensive to produce the modern consumer is a world away from buying a powerful, high quality refracting telescope. They also have other negative aspects associated with them in that they are often bulky and space consuming. The images viewed through refracting telescopes are also subject to color aberrations around the edges of the viewed object.

These problems were solved in 1733 by Isaac Newton who built the first reflector or reflecting telescope. Today these are also known as Dobsonian or Newtonian telescopes. These telescopes utilize mirrors to reflect light out a side opening to the eyepiece. Modern reflectors provide bigger bang for your buck because mirrors are cheaper to produce meaning they come with wider apertures. They are superior for viewing deep space images. They do come with drawbacks however. They are not as durable as their refractor counterparts and they require more maintenance. In addition to this the mirrors may need recoating after a number of years.

The new kid on the block these days is a hybrid design utilizing lenses and mirrors. These modern telescopes are based on a design, which was developed by Bernhard Schmidt and they have all the positive attributes of both refractor and reflector telescopes. This design is used in a range of scopes from small amateur backyard versions to professional observatory models. The one and only drawback is that they tend to be more expensive than the other two types of telescope.

Telescopes have come an incredibly long way in both design and technology since their formative years. Today a lot of modern telescopes are computerized and you view the image on your screen. The control interface allows the user to move and save co-ordinates in their computer so they can easily view the same point repeatedly. Computer controlled versions also allow photographic and video recording of the night sky.

Today it is easier than ever to get into astronomy and is an especially positive experience to share with the family. Decent introductory telescopes can be purchased online or at good department and specialty stores for under $300. These will let you introduce your kids to the night sky and give them a good appreciation of the cosmos. If you want to educate your kids more there are several Internet sites that are hooked up to more powerful telescopes in observatories around the globe. You can logon and in some cases control these telescopes from their website and get the feel of having your own observatory with having to leave your home or spend any money.

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