When we look at the moon, the light that we see is actually the light of the sun reflected by the moon. Half of the moon is always in sunlight and half is always in darkness. Even though half of the moon stays lit, or illuminated, by the sun, the moon appears to have different shapes on different nights. These shapes are called phases. Different phases occur because we see different amounts of the lighted half of the moon on different days. The more of the illuminated side of the moon we see, the larger the moon appears to be. The less of the illuminated side of the moon we see, the smaller the moon appears. For example, during the full moon phase, all of the lighted part of the moon is seen from Earth and the moon appears fully lit. During the new moon phase, when the whole moon appears very dark, only the non-lit part of the moon is visible to Earth. The names of all the phases of the moon are shown below.

Question

When we look at the moon, the light that we see is actually the light of the sun reflected by the moon. Half of the moon is always in sunlight and half is always in darkness. Even though half of the moon stays lit, or illuminated, by the sun, the moon appears to have different shapes on different nights. These shapes are called phases. Different phases occur because we see different amounts of the lighted half of the moon on different days. The more of the illuminated side of the moon we see, the larger the moon appears to be. The less of the illuminated side of the moon we see, the smaller the moon appears. For example, during the full moon phase, all of the lighted part of the moon is seen from Earth and the moon appears fully lit. During the new moon phase, when the whole moon appears very dark, only the non-lit part of the moon is visible to Earth. The names of all the phases of the moon are shown below.
Full Waning
Third Waning
Moon Gibbous Quarter Crescent
New Waxing
First Waxing
Moon Crescent Quarter Gibbous
These moon phases occur in a highly predictable pattern. New moon is always followed by waxing crescent, then first quarter, then waxing gibbous, then full moon, then waning gibbous, then third (or last) quarter, then waning crescent, then back to new moon. Then the cycle repeats. This cycle of phases of the moon are caused by the Moon's revolution around the Earth. One complete cycle of moon phases takes 29.5 days, or one month (think "moon-th").
How much of the lit portion of the moon do we see?
Date in 2020
Percent
Illuminated
Date in 2020
Percent
Illuminated
Date in 2020
Percent
Illuminated
Date in 2020
Percent
Illuminated
10/31
100
11/8
50
11/16
3
11/24
72
11/1
99
11/9
41
11/17
8
11/25
80
11/2
97
11/10
30
11/18
15
11/26
87
11/3
93
11/11
20
11/19
24
11/27
93
11/4
87
11/12
=
11/20
33
11/28
97
11/5
80
11/13
5
11/21
43
11/29
99
11/6
71
11/14
1
11/22
51
11/30
100
11/7
62
11/15

11/23
63

In order to receive full credit, please record your answers in full sentences.
Do not forget to number your responses.
1. Which two dates from the chart above would have nights with a full moon?
2. Halloween night 2020 had a full moon. Does this mean that the entire moon was lit by the sun on that night? Explain your answer.

GPT-4o mini · Answer

1. The two dates from the chart above that would have nights with a full moon are October 31, 2020, and November 30, 2020. On both of these dates, the percent illuminated is recorded as 100%, indicating that the entire lighted part of the moon was visible from Earth. 2. Yes, Halloween night 2020 had a full moon, which means that the entire moon was indeed lit by the sun on that night. When the moon is in the full phase, we see the whole illuminated side, resulting in the moon appearing fully lit. This alignment occurs when the Earth is between the moon and the sun, allowing us to see all of the moon's sunlit surface.