1. Telescopes

2. Galileo, Galileo Telescopes were first invented around the year 1600.
Galileo Galilei was an early astronomer who first used telescopes to view objects in our solar system.
He made many important discoveries including: the moon was covered in mountains and Jupiter had 4 large moons.

3. Modern Telescopes
Telescopes are instruments that collect and focus light and other forms of electromagnetic radiation.
Electromagnetic radiation is the invisible energy waves on the electromagnetic spectrum.
A telescope that uses lenses and mirrors to collect and focus visible light is called an optical telescope.
The two main types of optical telescopes are refracting telescopes and reflecting telescopes.

4. Electromagnetic Spectrum

5. Refracting vs. Reflecting telescopes
A refracting telescope, or refractor, is a telescope that uses glass lenses to collect and focus light into an image
These glass lenses bends light rays to focus them.
These were the earliest type of telescopes, used by Galileo to study objects in our solar system
A reflecting telescope, or reflector, uses mirrors instead of glass lenses.
The mirrors bounce light rays to focus them.
These were developed by Sir Isaac Newton around
The majority of telescopes used today are reflectors

6. Radio Telescopes
Simply put, radio telescopes are different from reflecting or refracting telescopes in that
they detect radio waves instead of light waves

7. Telescopes in SPACE
Since Earth’s atmosphere blocks many wavelengths of invisible light, astronomers have placed telescopes in space.
These telescopes include the Hubble Space Telescope, the Chandra X-Ray Observatory, and the Spitzer Space Telescope.
These different telescopes each observe a different wavelength on the electromagnetic spectrum (the spectrum of all visible and invisible light).

8. Which is Which?
Use your textbook to find the differences between the following three: Hubble Space Telescope Chandra X-Ray Observatory Spitzer Space Telescope