Quiz 3
1.
• Not graded.
2.
• In the following image, where would you need to be in
order to see the sun at your zenith during the day?
1. Anywhere along the
Tropic of Cancer
2. Anywhere along the
equator
3. At the south pole
4. At the north pole
5. Anywhere along the
Tropic of Capricorn
2.
• In the following image, where would you need to be in
order to see the sun at your zenith during the day?
1. Anywhere along the
Tropic of Cancer
2. Anywhere along the
equator
3. At the south pole
4. At the north pole
5. Anywhere along the
Tropic of Capricorn
To find an observer’s zenith, draw a line perpendicular to Earth’s surface and extend
it out into space. (Or, draw a line from the center of Earth, through the observer,
and then extend the line out into space.)
The observer
indicated with a
yellow dot is at a
latitude that
corresponds to
the Tropic of
Capricorn, and
his local time is
noon. If he
points along his
zenith, he will
point directly at
the sun.
Zenith
Related Questions
• On the day indicated in the previous image,
would a person who was on the Arctic Circle
ever say that the sun is at his zenith?
• On the day indicated in the previous image,
would a person who was on the Equator ever
say that the sun is at his zenith?
• What is the month corresponding to the previous
image?
3.
• If you were standing at a location along the
Tropic of Cancer at noon on December 21st,
how would you describe the position of the sun
in the sky? Note that the image used in the
previous problem is for December 21st.
1. Towards the south
2. Towards the north
3. Exactly at my zenith
3.
• If you were standing at a location along the
Tropic of Cancer at noon on December 21st,
how would you describe the position of the sun
in the sky? Note that the image used in the
previous problem is for December 21st.
1. Towards the south
2. Towards the north
3. Exactly at my zenith
The white line is the zenith for a person on the Tropic of Cancer at a local time of
noon. If the observer was looking along his zenith, he would need to look
southward in the sky to see the sun.
Zenith
Related Questions
• Two months after the date corresponding
to the previous image and at noon, in what
direction would a person on the Tropic of
Capricorn say the sun is? North? South?
4.
• If you live in the Arctic Circle, on June
21st, the sun will never set. On that day,
will the sun reach your zenith at noon?
1. No, because the sun's rays still strike
Earth's surface at an angle
2. Yes, just because.
4.
• If you live in the Arctic Circle, on June
21st, the sun will never set. On that day,
will the sun reach your zenith at noon?
1. No, because the sun's rays still strike
Earth's surface at an angle
2. Yes, just because.
Zenith for two
observers, one on
and one in the Arctic
Circle. In both
cases, the zenith
does not point directly
at the sun.
Related Questions
• Which observer on the previous image
would see the sun higher in the sky at
noon?
5.
• From the perspective of someone on Earth what position
of A-E best fits the Moon view in the lower-left-hand
corner? Note that in this image the sun is to the right.
1. C
2. B
3. A
4. E
5. D
5.
• From the perspective of someone on Earth what position
of A-E best fits the Moon view in the lower-left-hand
corner? Note that in this image the sun is to the right.
1. C
2. B
3. A
4. E
5. D
At I, a person on Earth says that the left side of the moon is sunlit.
At F, a person on Earth says that no part of the moon is sunlit.
Between I and F, the part that is sunlit must have shrunk.
F
H
Earth
I
Sun’s rays
G
6.
• Suppose that you live on the equator. At noon,
will you ever see a full moon?
1. Only at equinox
2. Yes
3. Only at solstice
4. No
6.
• Suppose that you live on the equator. At noon,
will you ever see a full moon?
1. Only at equinox
2. Yes
3. Only at solstice
4. No
1st quarter moon.
Full moon
Yellow dot is observer.
View from above the north pole. Sun is to the right.
Sunlight falls on the white parts. 1st quarter moon is
first visible at noon. Full moon is not visible at noon
(can’t draw line to it without hitting Earth).
7.
• From Earth, the entire side of the moon THAT WE CAN
SEE is illuminated on the day of the full moon. How
much of the moon's TOTAL surface is actually
illuminated by the sun?
1. 50%
2. 25%
3. 100%
4. 75%
7.
• From Earth, the entire side of the moon THAT WE CAN
SEE is illuminated on the day of the full moon. How
much of the moon's TOTAL surface is actually
illuminated by the sun?
1. 50%
2. 25%
3. 100%
4. 75%
Half of the moons surface is
(almost) always illuminated by the
sun. At new moon, we see the half
that is not illuminated. At full moon,
we see the half that is illuminated.
Related Questions
• During a total solar eclipse, how much of
the moon’s surface is illuminated by the
sun?
• During a total lunar eclipse, how much of
the moon’s surface is directly illuminated
by the sun?
8.
• A simple model of the Moon is that it orbits in Earth's
ecliptic plane and that its orbit is a perfect circle. If this
were true, which of the following would we expect?
1. We would never see the third quarter moon.
2. One eclipse per year.
3. An eclipse every month.
4. We would never see the first quarter moon.
8.
• A simple model of the Moon is that it orbits in Earth's
ecliptic plane and that its orbit is a perfect circle. If this
were true, which of the following would we expect?
1. We would never see the third quarter moon.
2. One eclipse per year.
3. An eclipse every month.
4. We would never see the first quarter moon.
9.
• What is the difference between an annular and total eclipse?
1. During a total eclipse, the sun is not on the line of nodes.
2. During an annular eclipse, the moon is closer to Earth.
3. During a total eclipse, the moon is farther from Earth.
4. During an annular eclipse, the full disk of the sun is not covered.
During a total eclipse the full disk of the sun is covered and all we
see is the faint corona. The moon is a bit further from Earth during
an annular eclipse.
9.
• What is the difference between an annular and total eclipse?
1. During a total eclipse, the sun is not on the line of nodes.
2. During an annular eclipse, the moon is closer to Earth.
3. During a total eclipse, the moon is farther from Earth.
4. During an annular eclipse, the full disk of the sun is not
covered. During a total eclipse the full disk of the sun is
covered and all we see is the faint corona. The moon is a bit
further from Earth during an annular eclipse.
Related Questions
• If the moon orbited the earth in a perfect
circle, would the time between annular and
total eclipses increase, decrease, or stay
the same.
10.
• Why don't we see a solar eclipse (either total or annular) every
month?
1. Because the same side of the moon always faces Earth.
2. Because the moon does not move in a circular orbit.
3. Because the moon casts an umbral and penumbral shadow.
4. Because the moon moves in a circular orbit.
5. Because Earth does not move in a circular orbit around the sun.
6. Because the moon orbits Earth in a plane that is slightly tilted to
the ecliptic plane.
10.
• Why don't we see a solar eclipse (either total or annular) every
month?
1. Because the same side of the moon always faces Earth.
2. Because the moon does not move in a circular orbit.
3. Because the moon casts an umbral and penumbral shadow.
4. Because the moon moves in a circular orbit.
5. Because Earth does not move in a circular orbit around the sun.
6. Because the moon orbits Earth in a plane that is slightly
tilted to the ecliptic plane.
11.
• Are the moon's phases caused by Earth
casting a shadow on the moon?
1. No. This is a common
misconception.
2. Yes
Related Questions
• Does the Earth ever cast a shadow on the
moon?
12.
• On the day that someone on Earth says it is a full moon, what will a
person on the moon say when they look at Earth?
1. About one-quarter of the part of Earth that I can see is sunlit.
2. About three-quarters of the part of Earth that I can see is sunlit.
3. About half of the part of Earth that I can see is sunlit.
4. Almost all of the part of Earth that I see is dark.
5. Almost all of the part of Earth that I can see is sunlit.
12.
• On the day that someone on Earth says it is a full moon, what will a
person on the moon say when they look at Earth?
1. About one-quarter of the part of Earth that I can see is sunlit.
2. About three-quarters of the part of Earth that I can see is sunlit.
3. About half of the part of Earth that I can see is sunlit.
4. Almost all of the part of Earth that I see is dark.
5. Almost all of the part of Earth that I can see is sunlit.
Full moon. Sun is far to the right.
Yellow dot is observer.
Related Questions
• The following is a typical sketch that we
use to show such things as when
someone will first be able to see the full
moon. Why is the right half of the moon
illuminated even though as drawn all of the
Sun’s rays would be blocked by Earth?
Full moon. Sun is far to the right.
13.
• From the perspective of someone on Earth, the moon
exhibits synchronous rotation. This means that the same
face of the moon is always facing Earth.
From the perspective of the sun, will the same face of
the moon always face the sun? That is, will someone on
the sun always see the same side of the moon?
1. No
2. Yes
13.
• From the perspective of someone on Earth, the moon
exhibits synchronous rotation. This means that the same
face of the moon is always facing Earth.
From the perspective of the sun, will the same face of
the moon always face the sun? That is, will someone on
the sun always see the same side of the moon?
1. No
2. Yes
B
A
D
C
At A, a person on
the sun cannot
see the red spot
on the moon. At
D, they can see
the red spot.
Related Questions
• At D, wouldn’t the Earth be blocking the
moon from view of the sun?
• How often would a person on the red dot
on the moon say that the sun is at his
zenith?
14.
• How often does a person on the equator
see a full moon?
1. At new moon
2. Once per month
3. Never
4. The Moon is always full
5. Twice per month
14.
• How often does a person on the equator
see a full moon?
1. At new moon
2. Once per month
3. Never
4. The Moon is always full
5. Twice per month
Related Questions
• If you lived on the Tropic of Capricorn,
would your answer to the previous
question change?