What is Telescopes? | Definition, Types, Formula & Examples
What is Telescopes?
A telescope is an instrument used to observe distant objects. Telescopes are commonly used to observe planets and stars. Some of the optical technologies used in telescopes are also used to make binoculars and cameras.
Important properties of Telescopes
The two most important properties of a telescope are:
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Light Gathering Ability – The more light a telescope can collect, the better you can see distant stars and faint objects in the night sky. This characteristic is usually determined by the aperture size of the telescope. The larger the aperture, the more light the telescope can collect.
Magnification – Telescope magnification describes how well the telescope can make objects appear.
Lenses and Mirrors
There are two main types of telescopes. A guy uses a lens to magnify an image. Telescopes that use lenses are called refracting telescopes. The other uses a mirror to focus light on the image. These telescopes are called reflecting telescopes.
Refracting Telescopes
Refractive telescopes use lenses to direct light to a specific focus so that the object will be magnified for the viewer. You can go here to learn more about lens refraction.
Reflecting Telescopes
Reflecting telescopes use mirrors instead of lenses to focus light. A concave mirror is used to collect light and bring it to a focal point. To get light out of the telescope, another mirror is used to direct the light to an eyepiece. There are many different reflector telescope designs, but Isaac Newton’s original design is still popular today.
History of the Telescope
The Hubble Space Telescope
One of the most famous telescopes in the world today is the Hubble Space Telescope. This telescope was put into orbit around the Earth in 1990 by space shuttle. Being outside of Earth’s atmosphere allows Hubble to see outer space without the need for background light. This allowed him to take amazing pictures of distant stars and galaxies.
Interesting Facts about Telescopes
The successor to the Hubble Space Telescope is the James Webb Space Telescope. Its launch is scheduled for 2021.
The first telescopes were used by maritime merchants and the military.
Most observatories are built on top of mountains where the air is thinner and cleaner.
Many astronomers today work remotely with actual telescopes. They control the telescope by computer on the Internet.
The world’s largest refracting telescope is located at the Yerkes Observatory in Wisconsin.