An Essay On The Telescope

THE TELESCOPE

Since the beginning of astronomy, astronomers had a unanimous goal: to see farther, better and in greater details.

The earliest known telescope was created by Hans Lippershey in 1608. Others have claimed to have made the discovery of telescope but according to documents, he is the earliest who has applied for the patent. The telescope had an convex objective lens and a concave eyepiece.

A year later, using such an early refracting telescope, Galileo Galilei, an Italian physicist and astronomer, noticed the craters and mountains on the moon as well as what was later coined as the Milky Way Galaxy.

Isaac Newton created the first 'practical' reflector in 1668, which included a small flat diagonal mirror to reflect the light to an eyepiece mounted on the side of the telescope. With time, telescopes became bigger and more sophisticated, and astronomers discovered more stars and galaxies. They were also able to calculate the distance between stars. Most of the large optical telescopes used for research today are reflectors.

The achromatic lens that first appeared in a 1733 telescope made by Chester Moore Hall, John Hadley's production of larger paraboloidal mirrors in 1721, the process of silvering glass mirrors introduced by Léon Foucault in 1857, and the adoption of long lasting aluminized coatings on reflector mirrors in 1932 evolved the telescopes to higher levels of performance and accuracy.

The era of radio telescopes along with radio astronomy begun with Karl Guthe Jansky's discovery of an astronomical radio source in 1931. In the 20th century, many types of telescopes were developed for a wide range of wavelengths from radio to gamma-rays. (infrared telescopes--700 nm/ 0.7 µm - 1000 µm/1 mm, ultra-violet teles...

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...mits information from and to the Goddard Space Flight Center in Greenbelt, Md. The telescope also has two main computers that manage the commands of pointing the telescope and other functions. Goddard sends the data to the Space Telescope Science Institute to analyze it.

The scientists didn't stop here. In their desire to better understand the universe, they designed The Next Generation Space Telescope (NGST) or the James Webb Space Telescope (JWST) that has been planned for launching in 2018. It is designed to make observations in the visible to the mid-infrared part of the electromagnetic spectrum.

This telescope is the result of an international collaboration of 17 countries lead by NASA, European Space Agency and Canadian Space Agency. It will help us determine the geometry of the universe and enable us to establish whether the universe will expand forever.