Deck 3: Moon Phases and Eclipses

Question 1

Predicting an eclipse is easy because all you have to do is keep track of where the Moon crosses the ecliptic.

Answer 1

True

Question 2

What is a new moon?

A) The lunar phase in which the first-quarter moon approaches full moon
B) The lunar phase in which Earth's shadow is cast on the Moon
C) The lunar phase in which the Moon's shadow is cast on Earth
D) The lunar phase in which sunlight illuminates only the far side of the Moon
E) The lunar phase in which sunlight illuminates the Earth facing side of the Moon

Answer 2

D

Question 3

As the illuminated part of the Moon grows larger from new to full, it is said to "wane".

Answer 3

False

Question 4

A "larger" Moon on the horizon is an optical illusion.

Question 5

The geometry of a solar eclipse is the same as that of a lunar eclipse.

Question 6

What are the two parts of a shadow during an eclipse?

A) total and partial
B) apogee and perigee
C) sidereal and synodic
D) waxing and waning
E) umbra and penumbra

Question 7

The Moon has a dark side that is never lit by the Sun.

Question 8

Any location on the Moon is sunlit for three weeks and is in darkness for one week as the Moon rotates.

Question 9

Since the Moon is about 0.5 degrees in angular diameter, about how far does it move in 24 hours across the background of the constellations?

A) 0.5 degrees
B) 1.0 degree
C) 2 degrees
D) 9 degrees
E) 13 degrees

Question 10

In most months, there are no eclipses.

Question 11

There is one side of the Moon that can never be seen directly by observers on Earth.

Question 12

When the full Moon passes through Earth's shadow, the eclipse is visible from anywhere on Earth's dark side.

Question 13

What is the length of time half of the Moon stays in sunlight per full rotation?

A) 29.53 days
B) 27.3 days
C) two weeks
D) one month
E) two months

Question 14

The angular diameters of the Moon and Sun vary slightly because the orbits of the Moon and Earth are slightly elliptical.

Question 15

When the Moon is totally eclipsed, the Moon is illuminated by some sunlight reflected by Earth's atmosphere.

Question 16

To see a solar eclipse, you have to be in Earth's shadow.

Question 17

What does a waning crescent moon mean?

A) The changing Moon between full moon and third quarter
B) The changing Moon between third quarter and new moon
C) The changing Moon between first quarter and full moon
D) The changing Moon between new moon and first quarter
E) The changing Moon between first and third quarters

Question 18

What produces the lunar phases?

A) The rotation of the Moon
B) The revolution of the Moon
C) The changing direction of sunlight
D) Earth's tilted axis relative to the Moon
E) The changing direction of Earth to the Moon

Question 19

The Moon moves slowly against the background of the constellations.

Question 20

Our calendar divides the year into 30-day periods in recognition of the synodic cycle of the Moon.

Question 21

Why can't the Moon always pass through the center of the umbra?

A) The Moon's rotation is slightly faster than its revolution around Earth.
B) The Moon's orbit is inclined by 5 degrees to the plane of Earth's orbit.
C) The Moon's synodic cycle changes a few minutes per cycle.
D) The Moon's orbit changes with the seasons.
E) The Moon is not in its full moon lunar phase.

Question 22

Calculate the angular diameter of the Moon with these known facts: Moon's linear diameter = 3480 km
Moon's average distance from Earth = 384,000 km
Number of arc seconds in 1 radian = 2.06 × 10⁵

A) 31 arc seconds
B) 187 arc seconds
C) 1750 arc seconds
D) 1870 arc seconds
E) 1910 arc seconds

Question 23

Between now and 2024, in which year will there be no opportunities for a solar eclipse?

A) 2015
B) 2016
C) 2018
D) 2021
E) 2024

Question 24

What does a waxing gibbous moon mean?

A) The changing Moon between full moon and third quarter
B) The changing Moon between third quarter and new moon
C) The changing Moon between first quarter and full moon
D) The changing Moon between new moon and first quarter
E) The changing Moon between first and third quarters

Question 25

Which part of the Sun is observable during a total solar eclipse?

A) core
B) solar disk
C) sunspots
D) photosphere
E) chromosphere

Question 26

What happens during a partial lunar eclipse?

A) Earth only partially enters the penumbra.
B) The Sun only partially enters the umbra.
C) The Moon only partially enters the penumbra.
D) Earth only partially enters the umbra.
E) The Moon only partially enters the umbra.

Question 27

What creates a total lunar eclipse?

A) The Sun passes completely through Earth's umbra.
B) The Moon passes completely through Earth's umbra.
C) The Moon passes through some of Earth's penumbra.
D) The Earth passes completely through the Moon's umbra.
E) The Earth passes through some of the Moon's penumbra.

Question 28

The ____ of the Moon and Sun vary slightly because the orbits of the Moon and Earth are slightly elliptical.

A) angular distance
B) linear diameter
C) linear distance
D) angular diameter
E) angular momentum

Question 29

If the Moon is too far from Earth during a solar eclipse, the _____ does not reach Earth's surface.

A) umbra
B) ecliptic
C) prominence
D) penumbra
E) solar disk

Question 30

What happens every 29.5 days?

A) The Moon's Saros cycle
B) The Moon's synodic cycle
C) The Moon's sidereal cycle
D) The Moon's ecliptic season
E) The Moon's chance for a partial eclipse

Question 31

What gives the Moon a coppery glow during a total eclipse?

A) Sunlight refracted through Earth's atmosphere
B) Sunlight reflected from Earth's surface
C) Not all of the sunlight is blocked out
D) The artificial light reflected up from Earth's surface
E) The spectral emissions of the gases that make up Earth's atmosphere.

Question 32

The diamond ring effect is a characteristic of which phenomena?

A) full moon
B) new moon
C) lunar eclipse
D) solar eclipse
E) solar prominence

Question 33

What happens during a penumbral lunar eclipse?

A) Earth only partially enters the penumbra.
B) Earth enters the entire penumbra.
C) The Moon partially enters the penumbra.
D) The Moon only partially enters the umbra.
E) Earth only partially enters the penumbra.

Question 34

At what point is the Moon closest to Earth?

A) apogee
B) perigee
C) umbra
D) penumbra
E) prominence

Question 35

What unit would best describe the linear diameter of a planetary body?

A) arc seconds
B) arc minutes
C) degrees
D) kilometers
E) radians

Question 36

If the Moon crosses Earth's shadow at the center of the umbra, how long will the entire eclipse last from start to finish?

A) 2 to 3 minutes
B) 7 minutes
C) 1 hour 45 minutes
D) 2 hours
E) 6 hours

Question 37

During a total solar eclipse, what part of the Sun is often visible that we normally cannot see?

A) core
B) CMEs
C) corona
D) photosphere
E) solar wind

Question 38

Due to the high temperatures of the gas, what color do prominences appear as during a solar eclipse?

A) copper
B) blue
C) pink
D) violet
E) teal

Question 39

At what point is the Moon farthest away from Earth?

A) apogee
B) perigee
C) umbra
D) penumbra
E) prominence

Question 40

The chromosphere is often marked by eruptions on the solar surface called ____.

A) solar flares
B) prominences
C) solar nodes
D) diamond rings
E) coronal mass ejections

Question 41

An plasma loop emerging from the solar surface is called a ___________.

A) prominence
B) penumbra
C) photosphere
D) corona
E) synodic period

Question 43

What is the safest way or method to observe a solar eclipse?

A) using a telescope
B) wearing sunglasses
C) by observing with your naked eyes
D) through a pinhole projection
E) through a UV filter held up to the sky

Question 44

What astronomical period takes 18 years 11 1/3 days to complete?

A) synodic cycle
B) lunar phase cycle
C) eclipse season
D) sidereal period
E) Saros cycle

Question 45

What are three common misconceptions about the Moon and how would you provide the correct explanation for those misconceptions?

Question 46

How would you explain to your friend, who knows nothing about astronomy, the way to predict the next eclipse of the Sun?

Question 47

Eclipses can occur only when, viewed from Earth, the Sun is near one of the _______________. of the Moon's orbit.

Question 48

Why do prominences appear pink during a solar eclipse?

A) Because of the high temperature of the gases
B) Because the photosphere being blocked out
C) Because of the placement of the lunar disk over the Sun
D) Because the prominences interact with Earth's magnetic field
E) Because different gases are being combined in the chromosphere

Question 49

A lunar eclipse can only occur when the Moon is ____

A) full
B) new
C) waxing
D) waning
E) rising

Question 50

After one _______________. of 18 years 11 1/3 days, the pattern of eclipses repeats.

Question 51

A(n) _______________ is the changing phase the week between first quarter and full moon.

Question 52

A(n) _______________ occurs when the Moon moves between Earth and the Sun.

Question 53

A solar eclipse can only occur when the Moon is ____

A) full
B) new
C) waning
D) waxing
E) rising

Question 54

Solar eclipses must occur at __________ moon.

A) crescent
B) new
C) full
D) waxing gibbous
E) waning gibbous

Question 55

Describe all that you would see during a total eclipse of the Sun.

Question 56

Total lunar eclipses tend to be darkest when the Moon's orbit carries it through the center of the _______________.

Question 57

Why can't a lunar eclipse happen at every full moon?

Question 58

Eclipses can occur only when, viewed from Earth, the Sun is near one of the ____ of the Moon's orbit.

A) nodes
B) points
C) phases
D) paths
E) ecliptics

Question 59

How many times does the Moon cross the ecliptic each month?

A) none
B) once
C) twice
D) three times
E) four times

Question 60

How many Saros cycles does it take for the same eclipse to occur at about the same location on Earth?

A) one cycle
B) three cycles
C) 18 cycles
D) 22 cycles
E) 54 cycles

Question 61

Explain why "the dark side of the Moon" is an incorrect statement.

Question 62

What is an eclipse season?

Question 63

The _______________ formula expresses the relationship of the linear (true) diameter, the angular (apparent) diameter, and the distance, of any object.

Question 64

The sidereal period is _______________ days long, the time it takes the Moon to circle the sky once and return to the same position relative to the stars.

Question 65

Because the _______________ of the Moon and the Sun vary slightly, the disk of the Moon is sometimes too small to cover the disk of the Sun.

Question 66

Why does the Moon appear reddish during a total lunar eclipse and not go completely dark?

Question 67

During the _______________ phase, sunlight illuminates the far side of the Moon, and the side you see is in darkness.

Question 68

A(n) _______________ can occur only at a full Moon if the Moon's path carries it through the shadow of Earth.

Question 69

If the Moon passes in front of the Sun when angular diameter of the Moon is smaller than that of the Sun, this produces a(n) __________ eclipse.

Question 70

What are the two conditions for an eclipse?

Question 71

The safest and simplest way to observe the partial phases of a solar eclipse is to use _______________  projection .

Question 72

If eclipses occur in repeatable patterns, then explain why an eclipse is not visible from the same place on Earth after one Saros cycle.

Question 73

If the Moon passes only partially into the umbra, we witness a(n) _______________.