Question 1

The celestial equator is defined as the

Accepted Answer

A)  line in the sky that is perpendicular to Earth's spin axis. 
B)  line traced in the sky by the Moon each month against the background stars. 
C)  line traced in the sky by the Sun over 1 year against the background stars. 
D)  band of constellations through which the Sun and Moon move in the sky. 
A)  line in the sky that is perpendicular to Earth's spin axis. 
B)  line traced in the sky by the Moon each month against the background stars. 
C)  line traced in the sky by the Sun over 1 year against the background stars. 
D)  band of constellations through which the Sun and Moon move in the sky.

Question 2

A lunar eclipse does not occur at every full Moon because the

Accepted Answer

A)  eclipse cannot occur after sunset. 
B)  plane of the Moon's orbit is at an angle to the plane of Earth's orbit. 
C)  path of the Sun is inclined at an angle of 5° to the ecliptic plane. 
D)  orbit of the Moon is not a perfect circle. 
A)  eclipse cannot occur after sunset. 
B)  plane of the Moon's orbit is at an angle to the plane of Earth's orbit. 
C)  path of the Sun is inclined at an angle of 5° to the ecliptic plane. 
D)  orbit of the Moon is not a perfect circle.

Question 3

(2 × 103)3 =

Accepted Answer

A)  6 × 106 
B)  8 × 106 
C)  6 × 109 
D)  8 × 109 
A)  6 × 106 
B)  8 × 106 
C)  6 × 109 
D)  8 × 109

Question 4

What is the difference in right ascension between the Moon and the Sun when the Moon is at quarter phase?

Accepted Answer

A)  6 hours 
B)  3 hours 
C)  12 hours 
D)  0 hours; they are in the same region of the sky. 
A)  6 hours 
B)  3 hours 
C)  12 hours 
D)  0 hours; they are in the same region of the sky.

Question 5

The equinoxes are located at the intersections of the

Accepted Answer

A)  horizon and the celestial equator. 
B)  ecliptic and the Moon's orbit. 
C)  ecliptic and the celestial equator. 
D)  ecliptic and the horizon. 
A)  horizon and the celestial equator. 
B)  ecliptic and the Moon's orbit. 
C)  ecliptic and the celestial equator. 
D)  ecliptic and the horizon.

Question 6

The constellations

Accepted Answer

A)  are 88 in number and cover the entire sky. 
B)  that the ancients imagined are constantly being augmented by newly invented constellations as new stars are being discovered. 
C)  are of historical interest only and play no role at all in modern astronomy. 
D)  consist of groups of stars that are all about the same distance from us. 
A)  are 88 in number and cover the entire sky. 
B)  that the ancients imagined are constantly being augmented by newly invented constellations as new stars are being discovered. 
C)  are of historical interest only and play no role at all in modern astronomy. 
D)  consist of groups of stars that are all about the same distance from us.

Question 7

Which of these directions does NOT always remain fixed in place relative to an observer's horizon?

Accepted Answer

A)  one of the points where the celestial equator contacts the horizon 
B)  summer solstice 
C)  zenith 
D)  north celestial pole 
A)  one of the points where the celestial equator contacts the horizon 
B)  summer solstice 
C)  zenith 
D)  north celestial pole

Question 8

How much of the overall sky is north of the celestial equator?

Accepted Answer

A)  less than one-half because of the tilt of the equator to the ecliptic plane 
B)  more than one-half because of the precession of the poles 
C)  exactly one-half 
D)  all of it, by definition 
A)  less than one-half because of the tilt of the equator to the ecliptic plane 
B)  more than one-half because of the precession of the poles 
C)  exactly one-half 
D)  all of it, by definition

Question 9

On the day of the vernal equinox (approximately March 21 each year), which of these conditions holds?

Accepted Answer

A)  The length of daylight is greatest on this day. 
B)  The Sun passes through an observer's zenith only on this day. 
C)  The Sun rises at its most northerly point on the horizon on this day. 
D)  Both day and night are almost exactly 12 hours long at all locations on Earth. 
A)  The length of daylight is greatest on this day. 
B)  The Sun passes through an observer's zenith only on this day. 
C)  The Sun rises at its most northerly point on the horizon on this day. 
D)  Both day and night are almost exactly 12 hours long at all locations on Earth.

Question 10

If an observer points toward the zenith today and points there again 45 days later, they will have pointed twice in the same direction relative to

Accepted Answer

A)  the horizon. 
B)  the Sun. 
C)  the Moon. 
D)  the fixed stars. 
A)  the horizon. 
B)  the Sun. 
C)  the Moon. 
D)  the fixed stars.

Question 11

Where should an observer expect to see the Sun in the sky if they were at the North Pole at the beginning of fall (about September 21)?

Accepted Answer

A)  on the horizon 
B)  at their zenith 
C)  at about 23.5° above the horizon all day 
D)  below their horizon all day 
A)  on the horizon 
B)  at their zenith 
C)  at about 23.5° above the horizon all day 
D)  below their horizon all day

Question 12

When an observer looks at the Moon in the sky, the terminator line (the division between the illuminated and the unilluminated regions) moves

Accepted Answer

A)  right to left. 
B)  left to right. 
C)  right to left from new to full and then left to right to new again. 
D)  left to right from new to full and then right to left to new again. 
A)  right to left. 
B)  left to right. 
C)  right to left from new to full and then left to right to new again. 
D)  left to right from new to full and then right to left to new again.

Question 13

When the northern hemisphere is experiencing winter, the

Accepted Answer

A)  Earth is closer to the Sun than it is during northern summer. 
B)  Earth is farther from the Sun than it is during the northern summer. 
C)  Earth is the same distance from the Sun as it is the rest of the year because Earth's orbit is circular with the Sun in the center. 
D)  southern hemisphere is experiencing winter also. 
A)  Earth is closer to the Sun than it is during northern summer. 
B)  Earth is farther from the Sun than it is during the northern summer. 
C)  Earth is the same distance from the Sun as it is the rest of the year because Earth's orbit is circular with the Sun in the center. 
D)  southern hemisphere is experiencing winter also.

Question 14

Astronauts on the Moon look back at Earth, whose diameter is about 12,800 km. Because the Earth-Moon distance is about 400,000 km and the Moon's diameter is about 3500 km, how much bigger or smaller will Earth appear in their sky than the Moon does in the sky?

Accepted Answer

A)  the same, obviously 
B)  114 times 
C)  3.7 times 
D)  0.27 times 
A)  the same, obviously 
B)  114 times 
C)  3.7 times 
D)  0.27 times

Question 15

How much of the Moon's surface is illuminated by the Sun at quarter-moon phase?

Accepted Answer

A)  about one-quarter 
B)  about one-half 
C)  only about one-tenth 
D)  about three-quarter. 
A)  about one-quarter 
B)  about one-half 
C)  only about one-tenth 
D)  about three-quarter.

Question 16

The Moon is visible in the sky in the daytime from most places on Earth

Accepted Answer

A)  only at full Moon phase, when it is very bright. 
B)  almost never-only during solar eclipses when the sky is dark. 
C)  about half the time, or for 2 weeks in every month. 
D)  at some time every day, but it is difficult to see because of the blue sky. 
A)  only at full Moon phase, when it is very bright. 
B)  almost never-only during solar eclipses when the sky is dark. 
C)  about half the time, or for 2 weeks in every month. 
D)  at some time every day, but it is difficult to see because of the blue sky.

Question 17

Which of these conditions holds for relative distances during a solar eclipse?

Accepted Answer

A)  The Moon is closer to the Sun than Earth is. 
B)  Earth is closer to the Sun than the Moon is. 
C)  The Moon and Earth are at the same distance from the Sun. 
D)  Because the condition for a solar eclipse is independent of relative distances of Earth and the Moon from the Sun, either the Moon or Earth can be closest to the Sun. 
A)  The Moon is closer to the Sun than Earth is. 
B)  Earth is closer to the Sun than the Moon is. 
C)  The Moon and Earth are at the same distance from the Sun. 
D)  Because the condition for a solar eclipse is independent of relative distances of Earth and the Moon from the Sun, either the Moon or Earth can be closest to the Sun.

Question 18

If an observer were on Mars, which of these bodies would never be seen as a crescent?

Accepted Answer

A)  Jupiter 
B)  Earth's Moon 
C)  Venus 
D)  Earth 
A)  Jupiter 
B)  Earth's Moon 
C)  Venus 
D)  Earth

Question 19

A solar eclipse can occur only when the

Accepted Answer

A)  Earth comes between the Moon and the Sun. 
B)  Moon comes between Earth and the Sun. 
C)  Sun, the Moon, and Earth form a precise right-angled triangle. 
D)  Sun comes between the Moon and Earth. 
A)  Earth comes between the Moon and the Sun. 
B)  Moon comes between Earth and the Sun. 
C)  Sun, the Moon, and Earth form a precise right-angled triangle. 
D)  Sun comes between the Moon and Earth.

Question 20

The MOST easily observed motions in the night sky are produced by the

Accepted Answer

A)  rotation of Earth on its axis. 
B)  revolution of Earth around the Sun. 
C)  motion of the planets along their orbits around the Sun. 
D)  motion of stars with respect to each other in the sky. 
A)  rotation of Earth on its axis. 
B)  revolution of Earth around the Sun. 
C)  motion of the planets along their orbits around the Sun. 
D)  motion of stars with respect to each other in the sky.

The celestial equator is defined as the

A lunar eclipse does not occur at every full Moon because the

(2 × 10³)³ =

What is the difference in right ascension between the Moon and the Sun when the Moon is at quarter phase?

The equinoxes are located at the intersections of the

The constellations

Which of these directions does NOT always remain fixed in place relative to an observer's horizon?

How much of the overall sky is north of the celestial equator?

On the day of the vernal equinox (approximately March 21 each year), which of these conditions holds?

If an observer points toward the zenith today and points there again 45 days later, they will have pointed twice in the same direction relative to

Where should an observer expect to see the Sun in the sky if they were at the North Pole at the beginning of fall (about September 21)?

When an observer looks at the Moon in the sky, the terminator line (the division between the illuminated and the unilluminated regions) moves

When the northern hemisphere is experiencing winter, the

Astronauts on the Moon look back at Earth, whose diameter is about 12,800 km. Because the Earth-Moon distance is about 400,000 km and the Moon's diameter is about 3500 km, how much bigger or smaller will Earth appear in their sky than the Moon does in the sky?

How much of the Moon's surface is illuminated by the Sun at quarter-moon phase?

The Moon is visible in the sky in the daytime from most places on Earth

Which of these conditions holds for relative distances during a solar eclipse?

If an observer were on Mars, which of these bodies would never be seen as a crescent?

A solar eclipse can occur only when the

The MOST easily observed motions in the night sky are produced by the

Gravitation and the Motion of the Planets

Light and Telescopes

Atomic Physics and Spectra

Exoplanets and the Formation of Planetary Systems

Formation of the Solar System

Earth and the Moon

The Other Terrestrial Planets

The Outer Planets

Vagabonds of the Solar System

The Sun: Our Extraordinary Star

Characterizing Stars

The Lives of Stars From Birth Through Middle Age

The Death of Stars

Black Holes: Matters of Gravity

The Milky Way Galaxy

Galaxies

Quasars and Other Active Galaxies

Cosmology

Astrobiology

Filters

Exam 1: Discovering the Night Sky

The celestial equator is defined as the

A lunar eclipse does not occur at every full Moon because the

(2 × 103)3 =

What is the difference in right ascension between the Moon and the Sun when the Moon is at quarter phase?

The equinoxes are located at the intersections of the

The constellations

Which of these directions does NOT always remain fixed in place relative to an observer's horizon?

How much of the overall sky is north of the celestial equator?

On the day of the vernal equinox (approximately March 21 each year), which of these conditions holds?

If an observer points toward the zenith today and points there again 45 days later, they will have pointed twice in the same direction relative to

Where should an observer expect to see the Sun in the sky if they were at the North Pole at the beginning of fall (about September 21)?

When an observer looks at the Moon in the sky, the terminator line (the division between the illuminated and the unilluminated regions) moves

When the northern hemisphere is experiencing winter, the

Astronauts on the Moon look back at Earth, whose diameter is about 12,800 km. Because the Earth-Moon distance is about 400,000 km and the Moon's diameter is about 3500 km, how much bigger or smaller will Earth appear in their sky than the Moon does in the sky?

How much of the Moon's surface is illuminated by the Sun at quarter-moon phase?

The Moon is visible in the sky in the daytime from most places on Earth

Which of these conditions holds for relative distances during a solar eclipse?

If an observer were on Mars, which of these bodies would never be seen as a crescent?

A solar eclipse can occur only when the

The MOST easily observed motions in the night sky are produced by the

Gravitation and the Motion of the Planets

Light and Telescopes

Atomic Physics and Spectra

Exoplanets and the Formation of Planetary Systems

Formation of the Solar System

Earth and the Moon

The Other Terrestrial Planets

The Outer Planets

Vagabonds of the Solar System

The Sun: Our Extraordinary Star

Characterizing Stars

The Lives of Stars From Birth Through Middle Age

The Death of Stars

Black Holes: Matters of Gravity

The Milky Way Galaxy

Galaxies

Quasars and Other Active Galaxies

Cosmology

Astrobiology

Filters

(2 × 10³)³ =