telescope:
an instrument that collects electromagnetic radiation from the sky and concentrates it for better observation
refracting telescope:
a telescope that uses a set of lenses to gather and focus light from distant objects
reflecting telescope:
a telescope that uses a curved mirror to gather and focus light from distant objects
What are the functions of the two lenses in an optical telescope?
to collect light and form an image at the back of the telescope - the eye piece magnifies the image produced by the objective lens
How does the atmosphere affect the images produced by optical telescopes?
motion from air pollution, water vapor, and light pollution distort the images made by the telescope
electromagnetic spectrum:
all of the frequencies or wavelengths of electromagnetic radiation
Why are X-ray telescopes placed in space?
because the atmosphere blocks most X-ray radiation from space
Explain the difference between an reflecting and refracting telescopes.
They uses different things to gather and focus light. Refracting uses lenses and a reflecting uses mirrors.
How are a telescope and the electromagnetic spectrum related?
A telescope is used to observe electromagnetic radiation and the electromagnetic spectrum is all of the wavelengths of electromagnetic radiation.
How does the atmosphere affect astronomical observations?
It blocks most electromagnetic radiation.
How does a reflecting telescope work?
It has a large curved mirror that reflects light to a flat mirror. A lens in the eyepiece then magnifies the image reflected from the flat mirror for observation.
How does a refracting telescope work?
It has an objective lens that gathers and focuses light, then another lens in the eyepiece magnifies the image produced by the objective lens.
What limits the size of a refracting telescope and why?
The size of the objective lens limits the size because if the lens is too large, it sags and distorts the images.
What advantages to reflecting telescopes have over refracting telescopes?
Reflecting can be more powerful because they are not limited by the size of the lens. Reflecting have mirrors that reflect all wavelengths of light to the same focal point where as lenses focus different wavelengths at slightly different distances.
List the types of electromagnetic radiation from longest wavelength to shortest wavelength.
radio waves, microwaves, infrared, visible light, ultraviolet, X rays, gamma rays
What tools do astronomers use to study visible light waves?
refracting and reflecting telescopes
What tools do astronomers use to study non-visible waves, such as radio waves, microwaves, infrared, ultraviolet, X rays, and gamma rays?
special nonoptical telescopes such as radio, ultraviolet, infrared, gamma-ray, and X-ray telescopes
Give 3 reasons why Hawaii s a good location for a telescope.
Hawaii has (1) very little light pollution, (2) very little air pollution, and (3) many tall volcanoes that are good sites for observatories.
Why doesn't the surface of a radio telescope have to be as flawless as the surface of a mirror in an optical telescope?
because radio waves are much larger than visible light waves
What limitation of a refracting telescope could be overcome by placing the telescope in space?
atmosphere-distorts radiation passing through it
light pollution-limits ability to see faint objects
earth's gravity-causes objective lens to sag, distorting images