Seans

The history of the telescope

Different types of telescopes and how they work

5 important discoveries

Telescopes are one of the main ways that astronomers explore the universe. Also they were and are used for looking at far away objects. The telescope was introduced to astronomy in 1609 by the great Italian scientist Galileo Galilei. 1608--In the Netherlands, Hans Lippershey discovers that holding two lenses up some distance apart bring objects closer. He applies for a patent on his invention. This is the first documented creation of a telescope. 1609--Galileo, after simply hearing that the device was invented, builds several telescopes of his own and turns them toward the heavens. This is the first documented case of the telescope being used to study the stars, planets, moon, and sun.. Source: http://www.antiquetelescopes.org/history.html

There are three main types of telescope – refractor, reflector, and catadioptric. Refractors work by bending light through a primary convex lens known as the ‘objective’ lens, and forcing the redirected light rays to converge at a space known as the ‘focal point’. From here, the light rays are focused – often by a prism or a second lens – into the eyepiece, where they are usually refracted again to form a prefect replica image. The telescope made famous by Galileo. A reflector telescope works on an entirely different principle. Instead of using lenses to capture and focus light, reflectors feature large-aperture “light buckets” or tubes that funnel light down the shaft towards a mirror, which then reflects the light into an eyepiece consisting of several different types of lenses. Reflector telescopes need lots of space and little background light A catadioptric telescope, also known as a ‘compound’ telescope, uses a combination of mirrors and lenses to increase the scope’s focal range and power while keeping weight, length and bulkiness to a minimum. Source: http://www.coolscopes.com/differenttypesoftelescopes.html

1) Jupiter Has Moons (1609 – 1612) 2) The Planets Move (2000 B.C. – 500 B.C.) 3) The Earth Moves (1543) 4) The Milky Way Is a Gigantic Disk of Stars (1780 – 1834) 5) The Universe Is Expanding (1924 – 1929) Source: http://science.discovery.com/convergence/100discoveries/big100/astronomy.html