Question 1

Suppose Earth,the Sun,and a planet are aligned along a straight line.The time interval until this alignment occurs again is a:

Accepted Answer

A)  sidereal period. 
B)  synodic period. 
C)  solar period. 
D)  tropical period. 
A)  sidereal period. 
B)  synodic period. 
C)  solar period. 
D)  tropical period.

Question 2

What is the phase of the Moon during a total solar eclipse?

Accepted Answer

A)  crescent 
B)  first quarter 
C)  full 
D)  new 
A)  crescent 
B)  first quarter 
C)  full 
D)  new

Question 3

Twice per year,when day and night are equal in length,the Sun is at one of two positions in the sky known as equinoxes.These points are the intersections of which two planes in the sky?

Accepted Answer

A)  the celestial equator and the ecliptic 
B)  the celestial meridian and the celestial equator 
C)  the ecliptic and the celestial meridian 
D)  the ecliptic and the arctic circle 
A)  the celestial equator and the ecliptic 
B)  the celestial meridian and the celestial equator 
C)  the ecliptic and the celestial meridian 
D)  the ecliptic and the arctic circle

Question 4

What is a tropical year?

Accepted Answer

A)  It is the time between seeing the Sun directly overhead in the tropics (between latitudes N 23.5° and S 23.5°) and next seeing it directly overhead again. 
B)  It is twice the period of time between seeing the Sun directly overhead in the tropics (between latitudes N 23.5° and S 23.5°) and next seeing it directly overhead again. 
C)  It is the time from one vernal equinox to the next. 
D)  It is the time between having Polaris as the north star and having Polaris again as the north star, divided by 26,000. 
A)  It is the time between seeing the Sun directly overhead in the tropics (between latitudes N 23.5° and S 23.5°) and next seeing it directly overhead again. 
B)  It is twice the period of time between seeing the Sun directly overhead in the tropics (between latitudes N 23.5° and S 23.5°) and next seeing it directly overhead again. 
C)  It is the time from one vernal equinox to the next. 
D)  It is the time between having Polaris as the north star and having Polaris again as the north star, divided by 26,000.

Question 5

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

Question 6

To which constellation will the north celestial pole be closest in the year 14,000 a.d.(see Figure 1-19c,Comins,Discovering the Essential Universe,6th ed.)?

Accepted Answer

A)  Lyra 
B)  Draco 
C)  Ursa Minor, because the north celestial pole never moves, by definition 
D)  Cepheus 
A)  Lyra 
B)  Draco 
C)  Ursa Minor, because the north celestial pole never moves, by definition 
D)  Cepheus

Question 7

On a particular day,the Sun is at the summer solstice and the Moon is at the vernal equinox.The lunar phase on that day is:

Accepted Answer

A)  quarter. 
B)  not predictable from this information. 
C)  full. 
D)  new. 
A)  quarter. 
B)  not predictable from this information. 
C)  full. 
D)  new.

Question 8

Over the period of one complete year,an observer at the South Pole would be able to see what fraction of the overall sky?

Accepted Answer

A)  50% 
B)  100% 
C)  somewhat less than 50%, except in a leap year 
D)  a variable amount, depending on the observer's longitude. 
A)  50% 
B)  100% 
C)  somewhat less than 50%, except in a leap year 
D)  a variable amount, depending on the observer's longitude.

Question 9

Why do we see different phases of the Moon?

Accepted Answer

A)  The illuminated half of the Moon becomes more or less visible from Earth as the Moon orbits Earth. 
B)  The Moon's distance from Earth changes as it moves in its elliptical orbit, thereby changing its apparent brightness. 
C)  Earth's shadow gradually moves over the Moon's surface as the Moon orbits Earth. 
D)  The Moon's rotation brings more or less of the illuminated hemisphere into view from Earth. 
A)  The illuminated half of the Moon becomes more or less visible from Earth as the Moon orbits Earth. 
B)  The Moon's distance from Earth changes as it moves in its elliptical orbit, thereby changing its apparent brightness. 
C)  Earth's shadow gradually moves over the Moon's surface as the Moon orbits Earth. 
D)  The Moon's rotation brings more or less of the illuminated hemisphere into view from Earth.

Question 10

When viewed from Earth,Venus subtends an angle of about 1 arc minute (1/60°)when it is at the closest point to Earth in its orbit.If you were watching Venus set in the west over a clear horizon (e.g.,ocean),how long would Venus take from the time it first reached the horizon to completely disappear below the horizon?

Accepted Answer

A)  It would be almost instantaneous (much less than 1 second). 
B)  second 
C)  about 4 minutes 
D)  about 4 seconds 
A)  It would be almost instantaneous (much less than 1 second). 
B)  second 
C)  about 4 minutes 
D)  about 4 seconds

Question 11

During which type of lunar eclipse does the Moon remain longest in Earth's shadow?

Accepted Answer

A)  penumbral 
B)  partial 
C)  total 
D)  For all three types of eclipse, the Moon remains in Earth's shadow for the same length of time. 
A)  penumbral 
B)  partial 
C)  total 
D)  For all three types of eclipse, the Moon remains in Earth's shadow for the same length of time.

Question 12

The change in the right ascension of the Sun between June 21 and September 22 is approximately:

Accepted Answer

A)  0 hours 0 minutes. 
B)  18 hours 0 minutes. 
C)  6 hours 0 minutes. 
D)  12 hours 0 minutes. 
A)  0 hours 0 minutes. 
B)  18 hours 0 minutes. 
C)  6 hours 0 minutes. 
D)  12 hours 0 minutes.

Question 13

If Earth "stood up straight" on the ecliptic instead of being tilted 23.5°,the Sun would be on the celestial equator and on the ecliptic:

Accepted Answer

A)  never. 
B)  all the time. 
C)  only at the equinoxes. 
D)  only during a solar eclipse. 
A)  never. 
B)  all the time. 
C)  only at the equinoxes. 
D)  only during a solar eclipse.

Question 14

The Moon does NOT look completely dark when it is in Earth's shadow during a total solar eclipse because:

Accepted Answer

A)  of light reflected from the clouds on Earth, the earthshine. 
B)  atmospheric refraction bends red solar light onto the Moon. 
C)  there are faint emissions from the tenuous lunar atmosphere, excited by solar wind bombardment. 
D)  there is a remnant glow from the hot lunar surface. 
A)  of light reflected from the clouds on Earth, the earthshine. 
B)  atmospheric refraction bends red solar light onto the Moon. 
C)  there are faint emissions from the tenuous lunar atmosphere, excited by solar wind bombardment. 
D)  there is a remnant glow from the hot lunar surface.

Question 15

The declination of the Sun on September 21 compared with that on March 21 is:

Accepted Answer

A)  47° greater. 
B)  about the same. 
C)  23.5° less. 
D)  23.5° greater. 
A)  47° greater. 
B)  about the same. 
C)  23.5° less. 
D)  23.5° greater.

Question 16

If the Moon is between the Sun and Earth and almost in line with the Sun,we call its phase:

Accepted Answer

A)  new Moon. 
B)  gibbous. 
C)  The Moon never goes between the Sun and Earth. 
D)  full Moon. 
A)  new Moon. 
B)  gibbous. 
C)  The Moon never goes between the Sun and Earth. 
D)  full Moon.

Question 17

The number 50,000 is written in powers-of-ten notation as:

Accepted Answer

A)  5 × 10⁴. 
B)  5 × 10⁵. 
C)  (50) × 10-³ = 5 × 10-². 
D)  5 × 10³. 
A)  5 × 10⁴. 
B)  5 × 10⁵. 
C)  (50) × 10-³ = 5 × 10-². 
D)  5 × 10³.

Question 18

During a total lunar eclipse,the Moon is:

Accepted Answer

A)  totally invisible since Earth blocks all light from reaching it. 
B)  barely visible because of "zodiacal light," sunlight reflected off dust grains in space. 
C)  barely visible because it glows slightly by its own light. 
D)  barely visible because of light passing through Earth's atmosphere. 
A)  totally invisible since Earth blocks all light from reaching it. 
B)  barely visible because of "zodiacal light," sunlight reflected off dust grains in space. 
C)  barely visible because it glows slightly by its own light. 
D)  barely visible because of light passing through Earth's atmosphere.

Question 19

Precession is the:

Accepted Answer

A)  slow coning motion of Earth's spin axis, similar to that of a spinning top. 
B)  gradual reversal of Earth's magnetic field. 
C)  motion of Earth along its orbital path during a year. 
D)  daily spinning motion of Earth, producing the apparent motion of the Sun and the stars. 
A)  slow coning motion of Earth's spin axis, similar to that of a spinning top. 
B)  gradual reversal of Earth's magnetic field. 
C)  motion of Earth along its orbital path during a year. 
D)  daily spinning motion of Earth, producing the apparent motion of the Sun and the stars.

Question 20

In the southern hemisphere,summertime occurs when:

Accepted Answer

A)  sunlight falls more directly on this hemisphere, heating it more than at other times of the year. 
B)  Earth's equator is parallel to the plane of its orbit. 
C)  sunlight falls less directly on this hemisphere, spreading the heat out over a greater area and thereby heating it more. 
D)  Earth is farthest from the Sun in its elliptical orbit. 
A)  sunlight falls more directly on this hemisphere, heating it more than at other times of the year. 
B)  Earth's equator is parallel to the plane of its orbit. 
C)  sunlight falls less directly on this hemisphere, spreading the heat out over a greater area and thereby heating it more. 
D)  Earth is farthest from the Sun in its elliptical orbit.

Suppose Earth,the Sun,and a planet are aligned along a straight line.The time interval until this alignment occurs again is a:

What is the phase of the Moon during a total solar eclipse?

Twice per year,when day and night are equal in length,the Sun is at one of two positions in the sky known as equinoxes.These points are the intersections of which two planes in the sky?

What is a tropical year?

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

To which constellation will the north celestial pole be closest in the year 14,000 a.d.(see Figure 1-19c,Comins,Discovering the Essential Universe,6th ed.)?

On a particular day,the Sun is at the summer solstice and the Moon is at the vernal equinox.The lunar phase on that day is:

Over the period of one complete year,an observer at the South Pole would be able to see what fraction of the overall sky?

Why do we see different phases of the Moon?

During which type of lunar eclipse does the Moon remain longest in Earth's shadow?

The change in the right ascension of the Sun between June 21 and September 22 is approximately:

If Earth "stood up straight" on the ecliptic instead of being tilted 23.5°,the Sun would be on the celestial equator and on the ecliptic:

The Moon does NOT look completely dark when it is in Earth's shadow during a total solar eclipse because:

The declination of the Sun on September 21 compared with that on March 21 is:

If the Moon is between the Sun and Earth and almost in line with the Sun,we call its phase:

The number 50,000 is written in powers-of-ten notation as:

During a total lunar eclipse,the Moon is:

Precession is the:

In the southern hemisphere,summertime occurs when:

Gravitation and the Waltz of the Planets

Light and Telescopes

Formation of the Solar System and Other Planetary Systems

Exoplanets

The Terrestrial Planets and Their Moons

The Outer Planets and Their Moons

Vagabonds of the Solar System

The Sun: Our Extraordinary Ordinary Star

Characterizing Stars

The Lives of the Stars From Birth Through Middle Age

The Deaths and Remnants of Stars

The Galaxies

Cosmology

Astrobiology

Filters

Exam 1: Discovering the Night Sky

Suppose Earth,the Sun,and a planet are aligned along a straight line.The time interval until this alignment occurs again is a:

What is the phase of the Moon during a total solar eclipse?

Twice per year,when day and night are equal in length,the Sun is at one of two positions in the sky known as equinoxes.These points are the intersections of which two planes in the sky?

What is a tropical year?

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

To which constellation will the north celestial pole be closest in the year 14,000 a.d.(see Figure 1-19c,Comins,Discovering the Essential Universe,6th ed.)?

On a particular day,the Sun is at the summer solstice and the Moon is at the vernal equinox.The lunar phase on that day is:

Over the period of one complete year,an observer at the South Pole would be able to see what fraction of the overall sky?

Why do we see different phases of the Moon?

During which type of lunar eclipse does the Moon remain longest in Earth's shadow?

The change in the right ascension of the Sun between June 21 and September 22 is approximately:

If Earth "stood up straight" on the ecliptic instead of being tilted 23.5°,the Sun would be on the celestial equator and on the ecliptic:

The Moon does NOT look completely dark when it is in Earth's shadow during a total solar eclipse because:

The declination of the Sun on September 21 compared with that on March 21 is:

If the Moon is between the Sun and Earth and almost in line with the Sun,we call its phase:

The number 50,000 is written in powers-of-ten notation as:

During a total lunar eclipse,the Moon is:

Precession is the:

In the southern hemisphere,summertime occurs when:

Gravitation and the Waltz of the Planets

Light and Telescopes

Formation of the Solar System and Other Planetary Systems

Exoplanets

The Terrestrial Planets and Their Moons

The Outer Planets and Their Moons

Vagabonds of the Solar System

The Sun: Our Extraordinary Ordinary Star

Characterizing Stars

The Lives of the Stars From Birth Through Middle Age

The Deaths and Remnants of Stars

The Galaxies

Cosmology

Astrobiology

Filters