Question 1

Remote sensing instruments have been used to:

Accepted Answer

A) map surfaces hidden beneath thick atmospheres 
B) measure the composition of atmospheres 
C) identify geological features 
D) watch weather patterns develop 
E) all of the above 
A) map surfaces hidden beneath thick atmospheres 
B) measure the composition of atmospheres 
C) identify geological features 
D) watch weather patterns develop 
E) all of the above

Question 2

The first astronomical radio source ever observed was:

Accepted Answer

A) the Andromeda Galaxy 
B) the galactic center,in the constellation Sagittarius 
C) thunderstorms 
D) the Earth 
E) Jupiter 
A) the Andromeda Galaxy 
B) the galactic center,in the constellation Sagittarius 
C) thunderstorms 
D) the Earth 
E) Jupiter

Question 3

Explain the difference between dispersion and diffraction.How can both phenomena be used to create a spectrum?

Accepted Answer

Dispersion is the wavelength dependence

Question 4

Cameras that use adaptive optics provide higher spatial resolution images primarily because:

Accepted Answer

A) they operate above the Earth's atmosphere 
B) they capture infrared light,which has a longer wavelength than visible light 
C) deformable mirrors are used to correct the blurring due to the Earth's atmosphere 
D) composite lenses correct for chromatic aberration 
E) they simulate a much larger telescope 
A) they operate above the Earth's atmosphere 
B) they capture infrared light,which has a longer wavelength than visible light 
C) deformable mirrors are used to correct the blurring due to the Earth's atmosphere 
D) composite lenses correct for chromatic aberration 
E) they simulate a much larger telescope

Question 5

Why is it difficult to view low surface brightness objects,such as the Andromeda Galaxy,with the naked eye? Does the view improve with the use of a telescope? What is needed to get a bright,clear view of the Andromeda Galaxy,as commonly seen in pictures?

Accepted Answer

The human eye has a low integration time

Question 6

Explain why stars twinkle when viewed from the ground.Would they twinkle if viewed from outer space?

Accepted Answer

Slight differences in air temperature ca

Question 7

In practice,the smallest angular size that one can resolve with a 10-inch telescope is governed by the:

Accepted Answer

A) blurring caused by the Earth's atmosphere 
B) diffraction limit of the telescope 
C) size of the primary mirror 
D) motion of the night sky 
E) magnification of the telescope 
A) blurring caused by the Earth's atmosphere 
B) diffraction limit of the telescope 
C) size of the primary mirror 
D) motion of the night sky 
E) magnification of the telescope

Question 8

The Voyager I spacecraft is currently 18 billion km from Earth and heading out of our Solar System.How long does it take radio messages from Voyager I to reach us?

Accepted Answer

A) 1.7 days 
B) 17 hours 
C) 17 days 
D) 17 weeks 
E) 17 minutes 
A) 1.7 days 
B) 17 hours 
C) 17 days 
D) 17 weeks 
E) 17 minutes

Question 9

Explain why the largest telescopes are not refracting telescopes.

Accepted Answer

The larger the refracting tele

Question 10

The dispersing element in a spectrograph could be a prism or a diffraction grating.

Accepted Answer

A) True 
 B)False

Question 11

High-speed computers have become one of an astronomer's most important tools.Which of the following does NOT require the use of a high-speed computer?

Accepted Answer

A) analyzing images taken with very large CCDs 
B) generating and testing theoretical models 
C) moving a telescope from object to object 
D) studying the evolution of astronomical objects or systems over time 
E) correcting for atmospheric distortion 
A) analyzing images taken with very large CCDs 
B) generating and testing theoretical models 
C) moving a telescope from object to object 
D) studying the evolution of astronomical objects or systems over time 
E) correcting for atmospheric distortion

Question 12

An object sits at the focal point of a parabolic mirror.At what distance from the mirror will its image be created?

Accepted Answer

A) It will be imaged at half the focal length. 
B) It will be imaged at the focal length. 
C) It will be imaged at twice the focal length. 
D) No image will be created (the beams would be reflected parallel to each other). 
E) The image is created on the other side of the mirror. 
A) It will be imaged at half the focal length. 
B) It will be imaged at the focal length. 
C) It will be imaged at twice the focal length. 
D) No image will be created (the beams would be reflected parallel to each other). 
E) The image is created on the other side of the mirror.

Question 13

The 305-meter Arecibo radio telescope in Puerto Rico has a resolution that is closest to that of:

Accepted Answer

A) the Hubble Space Telescope (0.1 arcsec) 
B) a human eye (1 arcmin) 
C) the Chandra X-ray telescope (0.5 arcsec) 
D) a 1-meter optical telescope (1 arcsec) 
E) one of the 10-meter Keck telescopes (0.0133 arcsec) 
A) the Hubble Space Telescope (0.1 arcsec) 
B) a human eye (1 arcmin) 
C) the Chandra X-ray telescope (0.5 arcsec) 
D) a 1-meter optical telescope (1 arcsec) 
E) one of the 10-meter Keck telescopes (0.0133 arcsec)

Question 14

Which property of light is responsible for chromatic aberration?

Accepted Answer

A) reflection 
B) interference 
C) dispersion 
D) diffraction 
E) magnification 
A) reflection 
B) interference 
C) dispersion 
D) diffraction 
E) magnification

Question 15

Why don't astronomers put all telescopes in space?

Accepted Answer

Building and launching a telescope into

Question 16

Why can you see fainter stars with an 8-inch telescope than you can see with your naked eye?

Accepted Answer

A) The telescope collects light over a larger area. 
B) The telescope magnifies the field of view. 
C) The telescope collects light over a wider range of wavelength than your eye. 
D) The telescope has a wider field of view. 
E) The telescope has a longer integration time than your eyes. 
A) The telescope collects light over a larger area. 
B) The telescope magnifies the field of view. 
C) The telescope collects light over a wider range of wavelength than your eye. 
D) The telescope has a wider field of view. 
E) The telescope has a longer integration time than your eyes.

Question 17

Discuss two advantages of flyby missions over orbiters in exploring planets and moons in the Solar System.

Accepted Answer

First,flyby missions are relat

Question 18

In 2009,the Cassini spacecraft made repeated orbits around Titan,Saturn's largest moon.If this spacecraft orbited at an altitude of 1,000 km above Titan's surface and its high-resolution camera had an angular resolution of 3 arcsec,how large an object could be resolved on Titan's surface?

Accepted Answer

The small angle approximation says θ = 2

Question 19

The highest spatial resolution images that we have of many planets' surfaces were obtained with the Hubble Space Telescope.

Accepted Answer

A) True 
 B)False

Question 20

What is the diffraction limit of a 4-m telescope observing at a wavelength of 650 nm?

Accepted Answer

θ = 2.06 × 10⁵ × (6.5

Exam 6: The Tools of the Astronomer

Remote sensing instruments have been used to:

The first astronomical radio source ever observed was:

Explain the difference between dispersion and diffraction.How can both phenomena be used to create a spectrum?

Cameras that use adaptive optics provide higher spatial resolution images primarily because:

Why is it difficult to view low surface brightness objects,such as the Andromeda Galaxy,with the naked eye? Does the view improve with the use of a telescope? What is needed to get a bright,clear view of the Andromeda Galaxy,as commonly seen in pictures?

Explain why stars twinkle when viewed from the ground.Would they twinkle if viewed from outer space?

In practice,the smallest angular size that one can resolve with a 10-inch telescope is governed by the:

The Voyager I spacecraft is currently 18 billion km from Earth and heading out of our Solar System.How long does it take radio messages from Voyager I to reach us?

Explain why the largest telescopes are not refracting telescopes.

The dispersing element in a spectrograph could be a prism or a diffraction grating.

High-speed computers have become one of an astronomer's most important tools.Which of the following does NOT require the use of a high-speed computer?

An object sits at the focal point of a parabolic mirror.At what distance from the mirror will its image be created?

The 305-meter Arecibo radio telescope in Puerto Rico has a resolution that is closest to that of:

Which property of light is responsible for chromatic aberration?

Why don't astronomers put all telescopes in space?

Why can you see fainter stars with an 8-inch telescope than you can see with your naked eye?

Discuss two advantages of flyby missions over orbiters in exploring planets and moons in the Solar System.

In 2009,the Cassini spacecraft made repeated orbits around Titan,Saturn's largest moon.If this spacecraft orbited at an altitude of 1,000 km above Titan's surface and its high-resolution camera had an angular resolution of 3 arcsec,how large an object could be resolved on Titan's surface?

The highest spatial resolution images that we have of many planets' surfaces were obtained with the Hubble Space Telescope.

What is the diffraction limit of a 4-m telescope observing at a wavelength of 650 nm?

Why Learn Astronomy

Patterns in the Skymotions of Earth

Motion of Astronomical Bodies

Gravity and Orbits

Light

The Birth and Evolution of Planetary Systems

The Terrestrial Planets and Earths Moon

Atmospheres of the Terrestrial Planets

Worlds of Gas and Liquid the Giant Planets

Planetary Adornments Moons and Rings

Dwarf Planets and Small Solar System Bodies

Taking the Measure of Stars

Our Starthe Sun

Star Formation and the Interstellar Medium

Evolution of Low-Mass Stars

Evolution of High-Mass Stars

Relativity and Black Holes

The Expanding Universe

Galaxies

The Milky Waya Normal Spiral Galaxy

Modern Cosmology

Large-Scale Structure in the Universe

Life

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