Question 1

The greater the wavelength of light, the greater its energy.

Accepted Answer

A) True 
 B)False  False

Question 2

Suppose an astronomer proposed to build a major observatory on the campus of your school. Would it make a good observing site? Explain why or why not.

Accepted Answer

Answers will vary somewhat with location, but in general campuses are bright environments that are poor observing sites from a light pollution standpoint. Other factors students may mention might include light from surrounding or nearby cities, excessive cloudiness or rain, windy area with a lot of turbulence, and low altitude with lots of atmosphere above.

Question 3

Which of the following conditions lead you to see an absorption line spectrum from a cloud of gas in interstellar space?

Accepted Answer

A) The cloud is extremely hot. 
B) The cloud is cool and lies between you and a hot star. 
C) The cloud is visible primarily because it reflects light from nearby stars. 
D) The cloud is cool and very dense, so that you cannot see any objects that lie behind it. 
A) The cloud is extremely hot. 
B) The cloud is cool and lies between you and a hot star. 
C) The cloud is visible primarily because it reflects light from nearby stars. 
D) The cloud is cool and very dense, so that you cannot see any objects that lie behind it. B

Question 4

How many atoms fit across the period at the end of this sentence?

Accepted Answer

A) hundreds 
B) billions 
C) thousands 
D) millions 
E) more than you could count in a lifetime 
A) hundreds 
B) billions 
C) thousands 
D) millions 
E) more than you could count in a lifetime

Question 5

What is an artificial star?

Accepted Answer

A) a meteor 
B) a satellite orbiting Earth 
C) a point of light in Earth's atmosphere created by a laser for the purpose of monitoring atmospheric fluctuations 
D) the unseen member of a binary star system 
E) a possible source of dark matter in the universe 
A) a meteor 
B) a satellite orbiting Earth 
C) a point of light in Earth's atmosphere created by a laser for the purpose of monitoring atmospheric fluctuations 
D) the unseen member of a binary star system 
E) a possible source of dark matter in the universe

Question 6

Which of the following is always true about images captured with X- ray telescopes?

Accepted Answer

A) They are always shown with colors that are not the true colors of the objects that were photographed. 
B) They are always very pretty. 
C) They always are made with adaptive optics. 
D) They show us light with extremely long wavelengths compared to the wavelengths of visible light. 
E) They always have very high angular resolution. 
A) They are always shown with colors that are not the true colors of the objects that were photographed. 
B) They are always very pretty. 
C) They always are made with adaptive optics. 
D) They show us light with extremely long wavelengths compared to the wavelengths of visible light. 
E) They always have very high angular resolution.

Question 7

Imagine that the sun began glowing half as bright at all visible wavelengths, but glowed much brighter in the infrared. How would this look to us, and why?

Accepted Answer

The sun would appear half as b

Question 8

X- rays from astronomical objects can only be detected from telescopes in space.

Accepted Answer

A) True 
 B)False

Question 9

The most common isotope of gold has atomic number 79 and atomic mass number 197. How many protons and neutrons does the gold nucleus contain? Assuming the gold is electrically neutral, how many electrons does it have?

Accepted Answer

The most common isotope of gol

Question 10

How does the light- collecting area of an 8- meter telescope compare to that of a 2- meter telescope?

Accepted Answer

A) The 8- meter telescope has 8 times the light- collecting area of the 2- meter telescope. 
B) The 8- meter telescope has 4 times the light- collecting area of the 2- meter telescope. 
C) The answer cannot be determined from the information given in the question. 
D) The 8- meter telescope has 16 times the light- collecting area of the 2- meter telescope. 
A) The 8- meter telescope has 8 times the light- collecting area of the 2- meter telescope. 
B) The 8- meter telescope has 4 times the light- collecting area of the 2- meter telescope. 
C) The answer cannot be determined from the information given in the question. 
D) The 8- meter telescope has 16 times the light- collecting area of the 2- meter telescope.

Question 11

One of the absorption lines of hydrogen has a rest wavelength of 656 nm (at rest means with respect to the observer, like in a lab). You observe several stars and measure the wavelength of this same hydrogen absorption line in each star. Based on the measured wavelength of this line, which star is moving towards the Earth the fastest?

Accepted Answer

A) 630 nm 
B) 670 nm 
C) 640 nm 
D) 680 nm 
E) 656 nm 
A) 630 nm 
B) 670 nm 
C) 640 nm 
D) 680 nm 
E) 656 nm

Question 12

What do astronomers mean by light pollution?

Accepted Answer

A) Light pollution means contamination of light caused by chemicals in the Earth's atmosphere. 
B) Light pollution is a type of air pollution created by lightweight gases such as hydrogen and helium. 
C) Light pollution is a term used to describe the appearance of the sky in regions that are crowded with stars. 
D) Light pollution is light from human sources that makes it difficult to see the stars at night. 
A) Light pollution means contamination of light caused by chemicals in the Earth's atmosphere. 
B) Light pollution is a type of air pollution created by lightweight gases such as hydrogen and helium. 
C) Light pollution is a term used to describe the appearance of the sky in regions that are crowded with stars. 
D) Light pollution is light from human sources that makes it difficult to see the stars at night.

Question 13

When atoms of an element are heated enough that they lose electrons, their emission and absorption spectra change.

Accepted Answer

A) True 
 B)False

Question 14

Lines of a particular element appear at the same wavelength in both emission and absorption line spectra.

Accepted Answer

A) True 
 B)False

Question 15

The resolution of a 10- meter telescope is about 0.01 arcsecond for visible light. Would you expect the angular resolution of a 10- meter radio telescope to be better than, equal to, or worse than 0.01 arcsecond? Explain.

Accepted Answer

It would be worse than 0.01 ar

Question 16

Why do astronomers need different telescope designs to observe across the electromagnetic spectrum?

Accepted Answer

A) Telescopes have to adapt to the greater distortion of the atmosphere at shorter wavelengths. 
B) Because light pollution is worse at radio wavelengths than visible wavelengths 
C) Photons of different energy behave differently and require different collection strategies. 
D) New telescopes incorporate new technology to increase their efficiency. 
E) Astronomers and engineers enjoy the challenge of making new telescope designs. 
A) Telescopes have to adapt to the greater distortion of the atmosphere at shorter wavelengths. 
B) Because light pollution is worse at radio wavelengths than visible wavelengths 
C) Photons of different energy behave differently and require different collection strategies. 
D) New telescopes incorporate new technology to increase their efficiency. 
E) Astronomers and engineers enjoy the challenge of making new telescope designs.

Question 17

Without telescopes or other aid, we can look up and see the Moon in the night sky because it

Accepted Answer

A) emits thermal radiation. 
B) reflects infrared light. 
C) glows through radioactive decay. 
D) emits visible light. 
E) reflects visible light. 
A) emits thermal radiation. 
B) reflects infrared light. 
C) glows through radioactive decay. 
D) emits visible light. 
E) reflects visible light.

Question 18

What is the purpose of interferometry?

Accepted Answer

A) It allows two or more small telescopes to achieve the angular resolution of a much larger telescope. 
B) It is designed to prevent light pollution from interfering with astronomical observations. 
C) It allows two or more small telescopes to achieve a larger light- collecting area than they would have independently. 
D) It reduces the twinkling of stars caused by atmospheric turbulence. 
A) It allows two or more small telescopes to achieve the angular resolution of a much larger telescope. 
B) It is designed to prevent light pollution from interfering with astronomical observations. 
C) It allows two or more small telescopes to achieve a larger light- collecting area than they would have independently. 
D) It reduces the twinkling of stars caused by atmospheric turbulence.

Question 19

Briefly explain why spectral lines are useful in determining the chemical composition of their source.

Accepted Answer

Every chemical element has a u

Question 20

Observatory construction sites: Consider the factors that go into selecting telescope construction sites. What type of site would you look for to build a large visible- light observatory? Where would you want to build an X- ray telescope? Would these be the same or different, and why?

Accepted Answer

For a visible- light telescope

The greater the wavelength of light, the greater its energy.

Suppose an astronomer proposed to build a major observatory on the campus of your school. Would it make a good observing site? Explain why or why not.

Which of the following conditions lead you to see an absorption line spectrum from a cloud of gas in interstellar space?

How many atoms fit across the period at the end of this sentence?

What is an artificial star?

Which of the following is always true about images captured with X- ray telescopes?

Imagine that the sun began glowing half as bright at all visible wavelengths, but glowed much brighter in the infrared. How would this look to us, and why?

X- rays from astronomical objects can only be detected from telescopes in space.

The most common isotope of gold has atomic number 79 and atomic mass number 197. How many protons and neutrons does the gold nucleus contain? Assuming the gold is electrically neutral, how many electrons does it have?

How does the light- collecting area of an 8- meter telescope compare to that of a 2- meter telescope?

What do astronomers mean by light pollution?

When atoms of an element are heated enough that they lose electrons, their emission and absorption spectra change.

Lines of a particular element appear at the same wavelength in both emission and absorption line spectra.

The resolution of a 10- meter telescope is about 0.01 arcsecond for visible light. Would you expect the angular resolution of a 10- meter radio telescope to be better than, equal to, or worse than 0.01 arcsecond? Explain.

Why do astronomers need different telescope designs to observe across the electromagnetic spectrum?

Without telescopes or other aid, we can look up and see the Moon in the night sky because it

What is the purpose of interferometry?

Briefly explain why spectral lines are useful in determining the chemical composition of their source.

Observatory construction sites: Consider the factors that go into selecting telescope construction sites. What type of site would you look for to build a large visible- light observatory? Where would you want to build an X- ray telescope? Would these be the same or different, and why?

A Modern View of the Universe

Discovering the Universe for Yourself

The Science of Astronomy

Making Sense of the Universe: Understanding Motion, Energy, and Gravity

Formation of the Solar System

Earth and the Terrestrial Worlds

Jovian Planet System

Asteroids, Comets, and Dwarf Planets: Their Nature, Orbits, and Impacts

Other Planetary Systems: the New Science of Distant Worlds

Our Star

Surveying the Stars

Star Stuff

The Bizarre Stellar Graveyard

Our Galaxy

A Universe of Galaxies

The Birth of the Universe

Dark Matter, Dark Energy, and the Fate of the Universe

Life in the Universe

Filters

Exam 5: Light: the Cosmic Messenger

The greater the wavelength of light, the greater its energy.

Suppose an astronomer proposed to build a major observatory on the campus of your school. Would it make a good observing site? Explain why or why not.

Which of the following conditions lead you to see an absorption line spectrum from a cloud of gas in interstellar space?

How many atoms fit across the period at the end of this sentence?

What is an artificial star?

Which of the following is always true about images captured with X- ray telescopes?

Imagine that the sun began glowing half as bright at all visible wavelengths, but glowed much brighter in the infrared. How would this look to us, and why?

X- rays from astronomical objects can only be detected from telescopes in space.

The most common isotope of gold has atomic number 79 and atomic mass number 197. How many protons and neutrons does the gold nucleus contain? Assuming the gold is electrically neutral, how many electrons does it have?

How does the light- collecting area of an 8- meter telescope compare to that of a 2- meter telescope?

What do astronomers mean by light pollution?

When atoms of an element are heated enough that they lose electrons, their emission and absorption spectra change.

Lines of a particular element appear at the same wavelength in both emission and absorption line spectra.

The resolution of a 10- meter telescope is about 0.01 arcsecond for visible light. Would you expect the angular resolution of a 10- meter radio telescope to be better than, equal to, or worse than 0.01 arcsecond? Explain.

Why do astronomers need different telescope designs to observe across the electromagnetic spectrum?

Without telescopes or other aid, we can look up and see the Moon in the night sky because it

What is the purpose of interferometry?

Briefly explain why spectral lines are useful in determining the chemical composition of their source.

Observatory construction sites: Consider the factors that go into selecting telescope construction sites. What type of site would you look for to build a large visible- light observatory? Where would you want to build an X- ray telescope? Would these be the same or different, and why?

A Modern View of the Universe

Discovering the Universe for Yourself

The Science of Astronomy

Making Sense of the Universe: Understanding Motion, Energy, and Gravity

Formation of the Solar System

Earth and the Terrestrial Worlds

Jovian Planet System

Asteroids, Comets, and Dwarf Planets: Their Nature, Orbits, and Impacts

Other Planetary Systems: the New Science of Distant Worlds

Our Star

Surveying the Stars

Star Stuff

The Bizarre Stellar Graveyard

Our Galaxy

A Universe of Galaxies

The Birth of the Universe

Dark Matter, Dark Energy, and the Fate of the Universe

Life in the Universe

Filters