Question 1

The "Local Bubble" is:

Accepted Answer

A) created by our Sun's solar wind, and extends well past Pluto's orbit. 
B) created by the bipolar jets of the young Sun, perpendicular to the ecliptic. 
C) about 100 pcs. across and transparent to extreme ultraviolet radiation. 
D) the region around the Milky Way where we can trace out its magnetic field. 
E) the cluster of galaxies our Milky Way and M-31 in Andromeda belong to. 
A) created by our Sun's solar wind, and extends well past Pluto's orbit. 
B) created by the bipolar jets of the young Sun, perpendicular to the ecliptic. 
C) about 100 pcs. across and transparent to extreme ultraviolet radiation. 
D) the region around the Milky Way where we can trace out its magnetic field. 
E) the cluster of galaxies our Milky Way and M-31 in Andromeda belong to.

Question 2

Unlike the ultraviolet photons originally emitted by the embedded stars of an emissionnebula, the photons emitted by the recombination of electrons with atoms:

Accepted Answer

A) do not escape the nebula. 
B) escape the nebula. 
C) are re-absorbed by neutral hydrogen atoms. 
D) bounce around inside the nebula. 
E) are scattered by the dust particles. 
A) do not escape the nebula. 
B) escape the nebula. 
C) are re-absorbed by neutral hydrogen atoms. 
D) bounce around inside the nebula. 
E) are scattered by the dust particles.

Question 3

What information does 21 cm radiation provide about the gas clouds?

Accepted Answer

A) their motion 
B) their distribution 
C) their density 
D) their temperature 
E) all of these 
A) their motion 
B) their distribution 
C) their density 
D) their temperature 
E) all of these

Question 4

Which is the least dense?

Accepted Answer

A) interstellar gas 
B) interstellar dust 
C) the atmosphere of Earth 
D) the atmosphere of Jupiter 
E) the atmosphere of the Sun 
A) interstellar gas 
B) interstellar dust 
C) the atmosphere of Earth 
D) the atmosphere of Jupiter 
E) the atmosphere of the Sun

Question 5

Charles Messier mapped the night sky and identified many objects now known to beemission nebulae in his search for objects that might be confused with:

Accepted Answer

A) comets. 
B) asteroids. 
C) galaxies. 
D) dark nebulae. 
E) reflection nebulae. 
A) comets. 
B) asteroids. 
C) galaxies. 
D) dark nebulae. 
E) reflection nebulae.

Question 6

Dark nebulae are opaque to all wavelengths of electromagnetic radiation.

Accepted Answer

A) True 
 B)False

Question 7

Contrast observations of ionized and neutral hydrogen in space.

Accepted Answer

Emission nebula glow bright red from the

Question 8

A reflection nebula is caused by:

Accepted Answer

A) starlight reflected off of a surface. 
B) sunlight reflected off of a surface. 
C) sunlight scattered by dust particles. 
D) starlight scattered by dust particles. 
E) emission by ionized gas. 
A) starlight reflected off of a surface. 
B) sunlight reflected off of a surface. 
C) sunlight scattered by dust particles. 
D) starlight scattered by dust particles. 
E) emission by ionized gas.

Question 9

Emission nebulae occur only near stars that emit large amounts of ________ electromagneticradiation.

Accepted Answer

The answer of Emission nebulae occur only near stars that...

Question 10

The spectra of interstellar gas clouds show that they have the same basic composition as:

Accepted Answer

A) interstellar dust. 
B) Earth's atmosphere. 
C) stars. 
D) asteroids. 
E) the Martian polar caps. 
A) interstellar dust. 
B) Earth's atmosphere. 
C) stars. 
D) asteroids. 
E) the Martian polar caps.

Question 11

If the spectra reveal stars A and B are identical, but star A looks bluer in color, then star B'slight has been ________ by interstellar dust.

Accepted Answer

The answer of If the spectra reveal stars A and...

Question 12

The form of electromagnetic radiation most effectively blocked by a dark nebula is ________.

Accepted Answer

The answer of The form of electromagnetic radiation most effectively...

Question 13

Complex molecules in the interstellar medium are found:

Accepted Answer

A) uniformly throughout the disk of the Galaxy. 
B) scattered evenly throughout the universe, a product of the Big Bang itself. 
C) only around the supergiant stars like Betelgeuse that make their heavy atoms. 
D) primarily in the dense dust clouds. 
E) on the surfaces of the coolest class K and M stars only. 
A) uniformly throughout the disk of the Galaxy. 
B) scattered evenly throughout the universe, a product of the Big Bang itself. 
C) only around the supergiant stars like Betelgeuse that make their heavy atoms. 
D) primarily in the dense dust clouds. 
E) on the surfaces of the coolest class K and M stars only.

Question 14

The overall dimming of starlight passing through dust clouds is called ________.

Accepted Answer

The answer of The overall dimming of starlight passing through...

Question 15

A dark cloud can be detected if it happens to block the light emitted by more distant stars.

Accepted Answer

A) True 
 B)False

Question 16

Molecular clouds are much warmer than typical interstellar gas clouds.

Accepted Answer

A) True 
 B)False

Question 17

What two things are needed to create an emission nebula?

Accepted Answer

A) interstellar gas and dust 
B) hydrogen fusion and helium ionization 
C) cool stars and much interstellar dust 
D) hot stars and interstellar gas, particularly hydrogen 
E) hydrogen gas and carbon dust 
A) interstellar gas and dust 
B) hydrogen fusion and helium ionization 
C) cool stars and much interstellar dust 
D) hot stars and interstellar gas, particularly hydrogen 
E) hydrogen gas and carbon dust

Question 18

Hydrogen is the major gas in the interstellar medium.

Accepted Answer

A) True 
 B)False

Question 19

In which wavelengths have the births of new stars been best mapped recently?

Accepted Answer

A) gamma rays 
B) extreme ultraviolet 
C) infrared 
D) microwave 
E) radio 
A) gamma rays 
B) extreme ultraviolet 
C) infrared 
D) microwave 
E) radio

Question 20

A "fuzzy" dark or light patch in the sky is called a:

Accepted Answer

A) nebula. 
B) cloud. 
C) galaxy. 
D) comet. 
E) dust lane. 
A) nebula. 
B) cloud. 
C) galaxy. 
D) comet. 
E) dust lane.

Exam 18: The Interstellar Medium: Gas and Dust Among the Stars

The "Local Bubble" is:

Unlike the ultraviolet photons originally emitted by the embedded stars of an emissionnebula, the photons emitted by the recombination of electrons with atoms:

What information does 21 cm radiation provide about the gas clouds?

Which is the least dense?

Charles Messier mapped the night sky and identified many objects now known to beemission nebulae in his search for objects that might be confused with:

Dark nebulae are opaque to all wavelengths of electromagnetic radiation.

Contrast observations of ionized and neutral hydrogen in space.

A reflection nebula is caused by:

Emission nebulae occur only near stars that emit large amounts of ________ electromagneticradiation.

The spectra of interstellar gas clouds show that they have the same basic composition as:

If the spectra reveal stars A and B are identical, but star A looks bluer in color, then star B'slight has been ________ by interstellar dust.

The form of electromagnetic radiation most effectively blocked by a dark nebula is ________.

Complex molecules in the interstellar medium are found:

The overall dimming of starlight passing through dust clouds is called ________.

A dark cloud can be detected if it happens to block the light emitted by more distant stars.

Molecular clouds are much warmer than typical interstellar gas clouds.

What two things are needed to create an emission nebula?

Hydrogen is the major gas in the interstellar medium.

In which wavelengths have the births of new stars been best mapped recently?

A "fuzzy" dark or light patch in the sky is called a:

Charting the Heavens: The Foundations of Astronomy

The Copernican Revolution: The Birth of Modern Science

Radiation: Information From the Cosmos

Spectroscopy: the Inner Workings of Atoms

Telescopes: The Tools of Astronomy

The Solar System: Comparative Planetology and Formation Models

Earth: Our Home in Space

The Moon and Mercury: Scorched and Battered Worlds

Venus: Earths Sister Planet

Mars: a Near Miss for Life

Jupiter: Giant of the Solar System

Saturn: Spectacular Rings and Mysterious Moons

Uranus and Neptune: The Outer Worlds of the Solar System

Solar System Debris: Keys to Our Origin

Exoplanets: Planetary Systems Beyond Our Own

The Sun: Our Parent Star

The Stars: Giants, Dwarfs, and the Main Sequence

Star Formation: a Traumatic Birth

Stellar Evolution: The Life and Death of a Star

Stellar Explosions: Novae, Supernovae, and the Formation of the Elements

Neutron Stars and Black Holes: Strange States of Matter

The Milky Way Galaxy: a Spiral in Space

Galaxies: Building Blocks of the Universe

Galaxies and Dark Matter: The Large-Scale Structure of the Cosmos

Cosmology: The Big Bang and the Fate of the Universe

The Early Universe: Toward the Beginning of Time

Life in the Universe: Are We Alone

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