In astronomy, a telescope is usually used to focus electromagnetic radiation so that astronomers can observe distant sources by using large effective areas to collect the most light. Among the most famous early observations by a telescope were those performed by Galileo on Jupiter’s moons that helped lead to the demise of the Earth-centred Universe. Show The resolution, θ of a telescope depends on its aperture, or mirror/dish diameter, D and the wavelength of the observed light, λ such that:
Due to the vast range of wavelengths of in the electromagnetic spectrum (from approximately 10-18 m to 100 km), many different telescope designs are needed. Radio Telescopes
Optical/Infrared Telescopes
Millimetre telescopes
X-ray telescopes
Gamma-ray telescopes
Can optical telescopes view the entire electromagnetic spectrum?Scientists use telescopes capable of viewing the universe across the entire electromagnetic spectrum.
Which electromagnetic waves do optical telescope collect?An optical telescope gathers and focuses light mainly from the visible part of the electromagnetic spectrum (although some work in the infrared and ultraviolet).
How does an optical telescope works?Early telescopes focused light using pieces of curved, clear glass, called lenses. However, most telescopes today use curved mirrors to gather light from the night sky. The shape of the mirror or lens in a telescope concentrates light. That light is what we see when we look into a telescope.
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