Telescopes

• 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.

Galileo, Galileo

• 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.

Modern Telescopes

Electromagnetic Spectrum

REFRACTING REFLECTING

• 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 1670.

• The majority of telescopes used today are reflectors

• 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

Refracting vs. Reflecting telescopes

• Simply put, radio telescopes are different from reflecting or refracting telescopes in that • they detect radio waves instead of

light waves

Radio Telescopes

• 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).

Telescopes in SPACE

Which is Which?Use your textbook to find the differences between the following three:

 

Hubble Space Telescope

 

Chandra X-Ray Observatory

 

 

Spitzer Space Telescope