TELESCOPE

 

            The telescope is undoubtedly one of the most important investigative tools in astronomy.  The telescope is a device used to create magnified images of distant objects.  This device provides a way to collect and analyze radiation from celestial objects, even those in the far reaches of the universe. 

            The Galilean telescope was first constructed in 1609 by Galileo Galilei.  It consists of a convergent lens and a divergent lens.  The convergent lens is what forms the image and the divergent lens is an eyepiece which is placed in front of the focus.  From these lenses, an upright image is produced.  This refracting telescope is still used in modern opera glassed, which are low-powered binoculars.

            Astronomical observations were restricted to visible wavelength until the 1930s when Karl Jansky and Grote Reber of the United States opened the radio "window".  Since the 1960s, the use of Earth-orbiting telescope systems has enabled astronomers to make observations in other spectral regions as well. Today, the telescope is used to explore every region of the electromagnetic spectrum from the shortest wavelengths (gamma rays), to the longest wavelengths (radio waves).  There are various forms of the original telescope that are used today.

                                               

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