Sci. 1-3 Telescopes- then and Now Pages 18-23

A. Telescopes- an instrument that collects electromagnet radiation from the sky and concentrates it for better observations.

B. Humans can see only visible light B. Humans can see only visible light. To detect other wavelengths of radiation, astronomers use special telescopes or detectors.

C. Types of Telescopes

1) Optical- telescope that collects light and forms an image at the back of the telescope.

a) Refracting and Reflecting telescopes are optical telescopes. b) Most professionals use reflecting telescopes.

2) Non-optical Telescopes- other than visible light

a) infrared- uses heat- unblocked by the atmosphere

b) Radio- uses radio waves- very sensitive – unblocked by the atmosphere

c) x-ray, ultraviolet, and gamma ray- each detects one type of electromagnetic waves- all are in space because our atmosphere blocks those waves. X-ray Ultraviolet Gamma ray

D. Telescopes are often linked together to function as one giant telescope.