Content Outline for Teaching - Potosi School District - Home

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Section 1
Content Outline
for Teaching
Radiation from Space
Exploring Space
Underlined words and
phrases are to be filled
in by students on the
Note-taking Worksheet.
A. Electromagnetic waves—carry energy through space and matter
1. Electromagnetic radiation includes radio waves, visible light, gamma
rays, X rays, ultraviolet light, infrared waves, and microwaves.
2. Electromagnetic spectrum—electromagnetic radiation arranged by wavelength
a. Forms of electromagnetic radiation differ in their frequencies—the number
of wave crests that pass a given point per unit of time.
b. The shorter the wavelength, the higher the frequency.
3. All electromagnetic waves travel at the speed of light,or 300,000 km/s
B. Optical telescopes—use light to produce magnified images
1. Refracting telescopes—have convex lenses
2. Reflecting telescopes—use concave mirror
3. Optical telescopes are often located in buildings called observatories, which
often have roofs that can be opened for viewing.
4. The Hubble Space Telescope, is located outside Earth’s atmosphere.
a. Mistake made in shaping largest mirror.
b. Once the mistake was repaired in 1999, the Hubble Space Telescope sent back
images of a large cluster of galaxies.
5. Active optics—computer helps correct poor images.
6. Adaptive optics—laser relays information to computer to adjust telescope’s
mirror and make images clearer
C. A radio telescope—studies radio waves that travel through space
1. Because radio waves pass freely through Earth’s atmosphere, radio telescopes
are usually useful 24 hours a day.
2. Scientists use information from radio waves to detect objects in space, map
the universe, and look for signs of life on other planets.
Discussion Question
What is the main difference between an optical telescope and a radio telescope?
Optical telescope uses visible light; and a radio telescope uses radio waves.
Exploring Space 43