1. The Tools of the Astronomer

2. The Telescope The telescope was invented in 1608.
A telescope is a device built to observe distant objects by making them appear closer.
Galileo’s telescope

3. Light Light is a form of electromagnetic radiation.
Scientists call the light you can see visible light.
Light travels in waves.
The distance between the crest of one wave and the crest of the next is called a wavelength.

4. Visible Light
White light shined through a prism spreads out to make a range of different colors with different wavelengths called a spectrum.

5. Stars produce energy
The electromagnetic spectrum includes the entire range of radio waves, microwaves, infrared radiation, visible light, ultraviolet radiation, X-rays, and gamma rays.
All of these waves are produced by stars.

6. The Electromagnetic Spectrum

7. Telescopes
Telescopes collect and focus light and other forms of electromagnetic radiation.
A telescope that uses lenses or mirrors to collect and focus visible light is called an optical telescope.

8. Optical Telescopes
There are two major types of optical telescopes: refracting and reflecting.

9. Types of Telescopes
A reflecting telescope uses a curved mirror to collect and focus light.
A refracting telescope uses convex lenses to gather and focus light.

10. What’s the difference? Refractor Reflector
Reflects image off a curved mirror
Image is right side up
Has only lenses
Image is upside down (inverted)
Uses light to form a visible image

11. Devices used to detect radio waves from objects in space are called radio telescopes.

12. Radio Telescopes
Most radio telescopes have curved, reflecting surfaces and are located on Earth’s surface.
The largest radio telescope is the Arecibo Radio Telescope in Puerto Rico.

13. Other types of telescopes
Other telescopes are designed to detect infrared radiation, ultraviolet radiation, X-rays, or gamma rays.
The sun in x-rays

14. Atmospheric Umbrella
Most ultraviolet radiation, X-rays, and gamma rays are blocked by Earth’s atmosphere.
To detect these wavelengths, astronomers have placed telescopes in space.

15. The Hubble Space Telescope
space visible light telescope
Was put in space in 1990
Produces extremely sharp visible images
Also collects ultraviolet and infrared radiation

16. Kepler Space Telescope

17. Looking for other planets

18. The Spitzer Space Telescope
surveys the sky in the infrared range of the spectrum.
Was launched into space in 2003

19. Gamma and X-ray Telescopes
On 26 Aug 2008, GLAST was renamed the "Fermi Gamma-ray Space Telescope" in honor of Enrico Fermi, a pioneer in high-energy physics.
The Chandra X-ray Observatory is a satellite launched on STS-93 by NASA on July 23, 1999.

20. http://app. discoveryeducation