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Telescopes

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Telescopes

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Presentation Transcript

  1. Telescopes Chapter 1 Section 2

  2. Telescopes • What color are Saturn’s Rings? • What does the surface of the moon look like? You could use a device called a telescope. Telescope- is an instrument that gathers electromagnetic radiation from objects in space and concentrates it for better observation

  3. Optical Telescopes • Most common of telescopes. • The optical telescope collects visible light and focuses it to a focal point for closer observation • A Focal Point is- the point where rays of light that pass through a lens meet or that reflect from a mirror and meet.

  4. Refracting Telescopes • Refracting Telescopes- uses a set of lenses to gather and focus light • Two Disadvantages • Images are not always focused because the lenses focus different colors of light at slight different distances, so images appear slightly blurred. • The size of a refracting telescope is also limited by the size of their objective lens.

  5. Reflecting Telescope • Reflecting Telescope- uses a curved mirror to gather and focus light from distant objects. • Advantages • Mirrors can be larger; therefore, the larger the mirror the more light being gathered • Flaws in the glass does not affect light because curved mirrors are polished. • Allow all colors of light from an object to be seen in focus at the same time

  6. Optical Telescopes-gather visible light -loss of brightness -lens expensive -larger the lens, more magnification, but more bubbles Better Hubble Space Telescope

  7. Optical Telescopes and the AtmosphereWhy mountains can help. • Light gathered by telescopes on Earth are affected by the atmosphere • Light pollution can make the sky look bright • Astronomers often place telescopes in dry areas to avoid moisture in the air.

  8. Optical Telescopes in Space • To avoid interference scientist have put telescopes in space.

  9. Importance of Light • Allows us to look back in time • Travels at 984,000,000 ft/sec. • A Light Year is: • The distance light travels in one year • Nearest Galaxy is Andromeda • 2 million light years away (fastest rocket-30,000 mi/hr)

  10. Summary • The bending of light called Refraction. • Passing white light through a prism separates or refracts the light into different colors. • Reflection occurs when light or any other wave bounces off an object. • Reflection enables you to see objects that don't produce their own light. • Mirrors

  11. Nonoptical Telescope-gathers invisible light http://www.youtube.com/watch?v=FSEA5_br7J0