Chapter 3

Question 1

If you could see the sun and stars during the daytime for several weeks, you would notice that the sun does which of the following?

Answer 1

moves slowly eastward relative to the stars

Question 2

Why does the sun move relative to the stars as observed from Earth?

Answer 2

It is due to Earth revolving around the sun.

Question 3

Why is the amount of solar heating less on a clear day in January at northern latitudes than on a clear day in July?

Answer 3

a. The sun is above the horizon for less than 12 hours in January in the north and at low sun angles, the received sunlight is spread over a larger surface area.

Question 4

When it is autumn in Asia, what season is it in Antarctica?

Answer 4

spring

Question 5

The five naked-eye planets and three telescopic planets that wander among the stars in the sky are always near which of the following?

Answer 5

ecliptic

Question 6

The Milankovitch hypothesis proposes that the ice ages on Earth are due to long-term changes in the amount of seasonal solar heating brought about by which of the following?

Answer 6

All of these choices are correct.

Question 7

Why are winter days colder than summer days?

Answer 7

The sun is up for less time in the winter.

Question 8

What is a reason for winter days being colder than summer days?

Answer 8

The sun is higher in the sky in the summer.

Question 9

Which of the following is true when it is winter in the southern hemisphere?

Answer 9

It is summer in the northern hemisphere.

Question 10

Which of the following is true for summer in the northern hemisphere?

Answer 10

It occurs during winter in the southern hemisphere.

Question 11

Due to Earth’s elliptical orbit, Earth is a little closer to the sun in January than in July. Because of this, which is true for winter in the southern hemisphere?

Answer 11

It is a little cooler than in the northern hemisphere.

Question 12

Due to Earth’s elliptical orbit, Earth is a little closer to the sun in January than in July.

Because of this, which is true for summer in the northern hemisphere?

Answer 12

It is a little cooler than in the southern hemisphere.

Question 13

Due to Earth’s elliptical orbit, Earth is a little closer to the sun in January than in July.

Answer 13

more in the southern hemisphere

Question 14

The postage stamp below shows the constellation Orion. Why would Orion look odd to residents of the northern hemisphere?

Answer 14

upside down.

Question 15

Identify the phase of the moon if the sun is at its March 21st vernal equinox position and the moon is located at the vernal equinox point on the ecliptic.

Answer 15

new.

Question 16

Identify the phase of the moon if the sun is at its March 21st vernal equinox position and the moon is located at the autumnal equinox point on the ecliptic.

Answer 16

full

Question 17

Identify the phase of the moon if the sun is at its March 21st vernal equinox position and the moon is located at the summer solstice point on the ecliptic.

Answer 17

first quarter

Question 18

Identify the phase of the moon if the sun is at its March 21st vernal equinox position and the moon is located at the winter solstice point on the ecliptic.

Answer 18

third quarter

Question 19

Identify the phase of the moon if at sunset the moon is near the eastern horizon.

Answer 19

full moon

Question 20

Identify the phase of the moon if at sunrise the moon is high in the southern sky for a mid-northern hemisphere observer.

Answer 20

third quarter

Question 21

For a mid-northern hemisphere observer, identify the phase of the moon if at sunset the moon is in the southeastern sky.

Answer 21

waxing gibbous

Question 22

For a mid-northern hemisphere observer, identify the phase of the moon if at sunrise the moon is in the southwestern sky.

Answer 22

waning gibbous

Question 23

About how many days must elapse between the first-quarter moon and the next new moon?

Answer 23

21

Question 24

If on March 1st the full moon is near the star Spica, when will the moon next be full?

Answer 24

29.5 days (synodic period)

Question 25

If on March 1st the full moon is near the star Spica, when will it next be near Spica?

Answer 25

27.3 days (sidereal period)

Question 26

How many times larger than the moon is the diameter of Earth’s umbral shadow at the moon’s distance? (Hint: See the image above.)
It is _____ times the moon’s size.

Answer 26

3

Question 27

The Earth’s diameter is about 4 times the diameter of the moon in kilometers. The moon is about 30 times Earth’s diameter distant from the Earth. Use the small-angle formula to calculate the angular diameter of Earth in degrees as seen from the moon.

Answer 27

2

Question 28

If a solar eclipse occurs on October 3rd, why can’t there be a lunar eclipse on October 10th?

Answer 28

The moon is new on October 3rd and not full until October 17th, the required phase for a possible lunar eclipse.

Question 29

If a solar eclipse occurs on October 3rd, why can’t there be a solar eclipse on December 28th that same year?

Answer 29

It is not eclipse season during that time.

Question 30

Which statement below best describes the motion of the moon relative to the stars?

Answer 30

The moon moves eastward relative to the stars about 13° per day.

Question 31

How does the moon’s motion relative to the stars compare to the sun’s motion relative to the stars?

Answer 31

The moon moves faster than the sun and in the same direction.

Question 32

How does one cycle of the moon’s motion relative to the stars compare to one cycle of the moon’s motion relative to the sun?

Answer 32

The cycle relative to the stars is shorter than the cycle relative to the sun.

Question 33

The time for one cycle of lunar phases is which of the following?

Answer 33

the same as the time for one cycle of the moon relative to the sun

Question 34

In one cycle of lunar phases, each crescent and gibbous phase has a duration of about one

Answer 34

week.

Question 35

If the moon reaches full phase on May 6th, it is at the _____ phase on May 17th.

Answer 35

waning crescent

Question 36

When does the third quarter phase moon rise?

Answer 36

midnight.

Question 37

What can be said about the maximum duration of lunar and solar eclipses?

Answer 37

A lunar eclipse can last up to almost six hours, and a solar eclipse up to 7.5 minutes.

Question 38

We can see total solar eclipses because of which of the following?

Answer 38

The angular diameters of the sun and the moon are almost equal

Question 39

Which of the following is true about the umbra of the moon’s shadow?

Answer 39

It is very dark, in total shadow, and its cone points away from the sun.

Question 40

During a total lunar eclipse, the moon

Answer 40

is often a reddish color and in Earth’s umbra.