1. Telescopes

2. How many galaxies can you see
Galaxy 3
Galaxy 1
Galaxy 4
Galaxy 2
Every star in the background is a galaxy
How many galaxies can you see

3. Exploring the Universe
Telescopes – are Fantastic!

4. What they find ! The Universe contains the most amazing objects
The Questions – How do they find them? What do they use?

5. Optical Telescopes Most common type of telescope
Used to study visible light from objects
Allows you to see millions of stars and other objects

6. Refracting Telescopes
Uses lenses to gather and focus light
Has an objective lens that bends light that passes through it and focuses the light to be magnified by an eyepiece

7. Reflecting Telescopes
Uses a curved mirror to gather and focus light
Focuses on all the colors of light
Gathers more light than refracting telescopes

8. Very Large Reflecting Telescopes
Several mirrors work together to collect light and focus it in the same area

9. Optical Telescopes and the Atmosphere
Air pollution, water vapor, and light pollution distort the images produced by optical telescopes.
Collects visible light and focuses it to a focal point for closer observation.

10. Other Telescopes – Hubble Space Telescope
Does not travel to stars, planets, or galaxies
Whirls around Earth at about 17,000 mph
About as long as a school bus
Has an unobstructed view of the universe
First major optical telescope to be placed in space

11. The Electromagnetic Spectrum
All of the frequencies or wavelengths of electromagnetic radiation

12. Detecting Electromagnetic Radiation
The Earth’s atmosphere blocks most invisible radiation from objects in space.
Each color of light is a different wavelength of electromagnetic radiation.
Radiation that can pass through the atmosphere includes some radio waves, microwaves, infrared light, visible light, and some ultraviolet light.

13. Nonoptical Telescopes
Detect radiation that cannot be seen by the human eye
Observes things at several wavelengths

14. Radio Telescopes Detect radio waves, not light waves
Much larger than optical telescopes

15. Linking Radio Telescopes
Produces detailed images of the universe
When linked together, they work like one giant telescope

16. Nonoptical Telescopes in Space
Placed in space because most electromagnetic waves are blocked by Earth’s atmosphere

17. Turn in your textbook to page 563.
In complete sentences, answer questions 1 and 2.
Write and answer in complete sentences questions 3, 4, 6, 9, 10, and 11.