Electromagnetic Spectrum & Telescopes and Light

Why do we put telescopes into space?

We want to get above Earth's atmosphere

Where is it optimal to build a telescope?

- In the desert (dry air, clear skies) - On mountaintops (above light pollution) - In remote areas

What problems due to the Earth's atmosphere affect observations? (3)

- Light pollution - Blurred images - The atmosphere absorbs most the EM specturm

T or F The primary function of a telescope is to magnify astronomical objects

False

Rank the various types of light on the electromagnetic spectrum according to their energy, from highest to lowest: - Gamma rays - X-rays - Ultraviolet - Visible - Infrared - Radio

Gamma rays X-rays Ultraviolet Visible Infrared Radio

Rank the various types of light on the electromagnetic spectrum according to their frequency, from highest to lowest: - Gamma rays - X-rays - Ultraviolet - Visible - Infrared - Radio

Gamma rays X-rays Ultraviolet Visible Infrared Radio

Which of the different wavelengths of light are completely absorbed in Earth's atmosphere and never reach the surface?

Gamma rays and X-rays

Which of the different wavelengths of light are able to partially penetrate Earth's atmosphere and reach the surface?

Infrared and Ultraviolet

Rank the various types of light on the electromagnetic spectrum according to their wavelength, from longest to shortest: - Gamma rays - X-rays - Ultraviolet - Visible - Infrared - Radio

Radio Infrared Visible Ultraviolet X-rays Gamma

Rank the various types of light on the electromagnetic spectrum according to their speed, from highest to lowest: - Gamma rays - X-rays - Ultraviolet - Visible - Infrared - Radio

Same

Which of the different wavelengths of light are able to completely penetrate Earth's atmosphere and reach the surface?

Visible and radio

Which have higher energy? a. Gamma rays b. Radio waves c. Same

a. Gamma rays

Which have higher frequency? a. Gamma rays b. Radio waves c. Same

a. Gamma rays

Which of the following wavelengths of light emitted by the Sun is most effectively blocked by the Earth's atmosphere? a. Gamma rays b. Visible c. Infrared d. Radio

a. Gamma rays

Which of the following wavelengths can be observed easily by a telescope on the Earth's surface? a. Radio b. Gamma ray c. Ultraviolet d. X-ray e. All of the above f. None of the above

a. Radio

Imagine you are the head of a funding agency that can afford to build one telescope. Which of the following proposed telescopes would be best to support? a. A radio telescope in orbit above the Earth b. A gamma ray telescope in orbit above the Earth c. An X-ray telescope located on a mountaintop in Hawaii d. An infrared telescope located in a valley in the California desert

b. A gamma ray telescope in orbit above the Earth

Imagine that you are the head of a funding agency that can afford to build one telescope. Which of the following proposed telescopes would be best to support? a. A radio telescope in orbit around the Earth b. An ultraviolet telescope in orbit around the Earth c. An X-ray telescope located in New Mexico

b. An ultraviolet telescope in orbit around the Earth

Which have a longer wavelength? a. Gamma rays b. Radio waves c. Same

b. Radio waves

Some telescopes are placed in space above Earth's atmosphere primarily for which of the following reasons? a. The light being sent out from the telescopes can be blocked by Earth's atmosphere b. The light from stars can be blocked by Earth's atmosphere c. To be closer to the stars d. Astronomers want to observe continuous spectra from stars rather than absorption spectra

b. The light from stars can be blocked by Earth's atmosphere

Which of the following is NOT one of the reasons we put telescopes in space? a. To get above the Earth's atmosphere b. To be closer to the stars c. To observe wavelengths of light blocked by Earth's atmosphere d. To avoid light pollution e. All of the above are reasons we put telescopes in space

b. To be closer to the stars

Which of the following wavelengths of light is most effectively blocked by the Earth's atmosphere? a. Radio b. Visible c. Gamma rays d. Infrared

c. Gamma rays

How are gamma rays different from radio waves? a. Gamma rays are a form of light waves and radio waves are a form of sound waves b. Gamma rays are made of different "stuff" than radio waves c. Gamma rays have higher energy and shorter wavelength than radio waves d. Gamma rays have more energy and travel at a higher speed than radio waves e. Gamma rays have a shorter wavelength and lower energy than radio waves

c. Gamma rays have higher energy and shorter wavelength than radio waves

A reflecting telescope uses a _____________ to focus light; a refracting telescope uses a _____________ to focus light a. Mirror, mirror b. Lens, lens c. Mirror, lens d. Lens, mirror

c. Mirror, lens

Which have higher speed? a. Gamma rays b. Radio waves c. Same

c. Same

Which of the following would be true about comparing gamma rays and radio waves? a. The radio waves would have lower energy and would travel slower than gamma rays b. The gamma rays would have shorter wavelength and a lower energy than radio waves c. The radio waves would have a longer wavelength and travel the same speed as gamma rays d. The gamma rays would have a longer wavelength and would travel faster than radio waves e. The radio waves would have a shorter wavelength and higher energy than gamma rays

c. The radio waves would have a longer wavelength and travel the same speed as gamma rays

Which of the following is not a form of light? a. Radio waves b. Microwaves c. X-rays d. All of the above are a form of light e. None of the above are a form of light

d. All of the above are a form of light

Which of the following wavelengths can be observed easily by a telescope on the Earth's surface? a. Gamma ray b. X-ray c. Ultraviolet d. Radio e. All of the above

d. Radio

Which of the following is not something to consider about a location when building a research-grade telescope on Earth? a. The remoteness of the area (away from light pollution) b. The humidity of the site (low humidity preferred) c. The elevation (mountaintops preferred) d. The proximity to the astronomer (closer is better, to be convenient)

d. The proximity to the astronomer (closer is better, to be convenient)

The portion of the electromagnetic spectrum that our eyes are sensitive to is a. Infrared light b. Radio waves c. Gamma rays d. Visible light e. More than one of the above

d. Visible light