Before we dive into the details around the Waning Crescent Moon, let’s first have a brief look at the moon in general.
A Quick Look at the Moon
After the Sun, the Moon is the brightest object in our sky. A big part of it is because of its distance from Earth. At 385,000km (240,000 miles), it is our closest celestial neighbor. Also, it is our planet’s only natural satellite.
We have sent many spacecraft to other planets, moons, and other objects in the solar system. However, aside from Earth, the Moon is the only other place where humans have landed and set foot on.
There are more than 200 moons discovered in the solar system. The biggest one is Jupiter’s moon, Ganymede, which is even larger than Mercury. Overall, the Earth’s Moon is the fifth largest of the known natural satellites in the solar system.
With its solid surface, the Moon has craters which are the results of impacts from comets, asteroids, and other objects that bang on its surface.
The Moon, like Earth, does not generate light. Though it is the brightest object that we can see at night, it only reflects light from the Sun. Because of that, it has a dayside and a nightside.
We get to see different portions of these sides as the Moon moves around Earth. This movement is the reason why the Moon appears different throughout the month.
The Eight Lunar Phases
The Moon goes through a series of apparent changes every month. One lunar cycle takes 29.5 days to complete. There are eight phases in this cycle, during which the Moon appears in different shapes as seen from Earth.
Moon Phase | Important NotesPhase |
---|---|
🌑New Moon | - 0% illumination - First primary phase - Earth-Moon-Sun alignment - The nightside of the Moon faces Earth |
🌒Waxing Crescent | - 0.1% to 49.9% illumination - Intermediate phase - The first sliver of moonlight is seen - The sunlit portion increases |
🌓First Quarter | - 50% illumination - Second primary phase - The Moon, Earth, and Sun form a right angle |
🌔Waxing Gibbous | - 50.1% to 99.9% illumination - Intermediate phase - The sunlit portion continues to increase |
🌕Full Moon | - 100% illumination - Third primary phase - Earth-Moon-Sun alignment - The dayside of the Moon faces Earth |
🌖Waning Gibbous | - 99.9% to 50.1% illumination - Intermediate phase - The sunlit portion decreases |
🌗Last Quarter | - 50% illumination - Fourth primary phase - Also called the Third Quarter Moon phase - The Moon, Earth, and Sun form a right angle |
🌘Waning Crescent | - 49.9% to 0.1% illumination - Intermediate phase - The sunlit portion continues to decrease - Gives way to the next New Moon phase |
What is a Waning Crescent Moon?
The Waning Crescent Moon is the eighth and last phase of the Moon. It is an intermediate phase which is like the transition phase between the Last Quarter and the New Moon.
When it comes to Moon phases, “waning” means decreasing. It means that the visible portion of the Moon is shrinking. This time, the Moon has a sickle-like shape and the sunlit part is less than the dark portion. It becomes smaller over time, from 49.9% to 0.1% illumination.
When it becomes invisible, the Waning Crescent phase ends and the New Moon enters. This marks the start of yet another Moon cycle.
The Waning Crescent Moon is nicknamed the “old moon” because it gives us a last glimpse of a lunar cycle. It is followed by the brief phase of the New Moon. After this dark phase is the Waxing Crescent Moon, which is also called the “young moon.” The thin crescent gives us the first look at the new lunar cycle.
An Old Moon
To better understand the Waning Crescent Moon or the old Moon, let us see where it fits in the context of the lunar cycle.
The lunar cycle starts with a New Moon when the Earth, Moon, and Sun are in a straight line. With the Moon in the middle, one side faces the Sun, while the other faces Earth. The Sun-facing side is illuminated while the side facing us is in darkness. Also, during this phase, the Moon rises and sets together with the Sun, so we cannot see it at night.
The Waxing Crescent Moon follows the New Moon. Also called the young moon, it marks the first appearance of the Moon after the invisible phase. The waxing phase continues until half of the Moon is lit during the First Quarter phase.
As the Moon continues on its counterclockwise trip around the Sun, it will enter the Waxing Gibbous phase. It is when more than half of it is lit up. After that, the lunar disk will be 100% illuminated during the Full Moon. The night sky will be especially bright during this phase.
After the Full Moon, the waning phases will follow, where the illuminated portion decreases. It will lose a small fraction during the Waning Gibbous Moon phase. The Last Quarter, also called the Third Quarter phase, will follow. It is a Half-Moon like the First Quarter but is lit on the opposite side.
As the lunar cycle nears completion, it will continue to shrink during the Waning Crescent Moon phase. Less than half of the Moon is sunlit until it becomes totally dark. This time, it has completed a full circle around Earth. It will be back from where it started in the New Moon where the Earth, Moon, and Sun, are in a straight line.
When Does a Waning Crescent Moon Occur?
The Waning Crescent Moon occurs after the Last Quarter and before a New Moon. It is an intermediate phase that serves as a transition between the two primary phases before and after it.
The Waning Crescent Moon is easy to remember because it marks the final phase of the Moon.
How Long Does the Waning Crescent Moon Last?
A lunar month is 29.5 days long. This is the time between two consecutive New Moons.
Intermediate phases like the Waning Crescent Moon last longer than the primary phases. On average, this phase lasts around 6 days. Other intermediate phases are Waxing Crescent, Waxing Gibbous, and Waning Gibbous. Each of these accounts for about 21.6% of the lunar cycle.
The primary phases are when the Sun, Moon, and Earth are in exact position, whether they are in a straight line or at a right angle. These astronomical bodies are in constant motion so they do not stay fixed in these positions. This is why the New Moon, First Quarter, Full Moon, and Last Quarter last around 3.4% of the cycle, or only about a day.
Which Side of the Moon Can We See?
The monthly dance of the Moon around Earth is responsible for its apparent changes in shapes. Throughout the different phases, the amount of the Moon that is illuminated is the same wherever you are on Earth. However, the location from which we observe it affects which side appears lit up.
The sky appears to be rotated by 180° from the north and south of the equator. Just like how the seasons are opposite in the northern and southern hemispheres, the orientation of the night sky is flipped too!
During the Waning Crescent Moon phase, from the northern hemisphere, you will see the left side of the Moon lit up. It is the opposite if you are observing it from the southern hemisphere. It is the same for all the waning phases of the Moon, or when it seems to be shrinking.
From the equator, the Moon is either illuminated on the upper or lower side. In the last phase of the Moon, the Waning Crescent will look like a smiley face as it rises. The upper side of it is visible when it sets.
Observers’ Location | Waxing Phases | Waning Phases |
---|---|---|
Northern Hemisphere | Right side | Left side |
Southern Hemisphere | Left side | Right side |
Equator | Upper part (moonrise) Lower part (moonset) | Lower part (moonrise) Upper part (moonset) |
Moonrise and Moonset Times
The Moon, Sun, stars and other objects in the sky appear to rise and set on our horizon. The Earth takes about 24 hours (23 hours, 56 minutes, and 4 seconds) to rotate on its axis. It moves in a counterclockwise direction, from west to east. This is why all astronomical objects in our sky rise from the east and set in the west.
On a New Moon, the Moon rises with the Sun. It rises more lately as it advances through the lunar cycle. The Waning Crescent Moon rises after midnight at around 3 am. With that said, it is up in the sky before dawn until early in the afternoon. It is at its highest point around 9 am.
Since the Waning Crescent Moon is above the horizon until 3 pm, we can sometimes see it in daylight. Still, the best time to see the daytime Moon is during the First Quarter and the Last Quarter.
Moon Phase | Average Moonrise and Moonset Times |
---|---|
🌑New Moon | 6 am–6 pm |
🌒Waxing Crescent | 9 am–9 pm |
🌓First Quarter | Noon–Midnight |
🌔Waxing Gibbous | 3 pm–3 am |
🌕Full Moon | 6 pm–6 am |
🌖Waning Gibbous | 9 pm–9 am |
🌗Last Quarter | Midnight–Noon |
🌘Waning Crescent | 3 am–3 pm |
Venus and the Crescent Moon
Venus is the hottest planet in the solar system. It is also the third brightest object in our sky after the Sun and Moon. It can be visible in the morning and at night.
In the past, people did not realize that what they saw was the same thing. As a result, it is called both the “morning star” and the “evening star.”
During the Waning Crescent phase, we can see the morning star close to the Moon. The moonrise is at around 3 am, so we can see these two objects best when the Sun has not yet totally risen.
Conversely, when we see Venus after sunset (aka the evening star), it means that the Waxing Crescent Moon is nearby.
Earthshine and the Crescent Moon
During the Waning Crescent phase, only a small part of the Moon reflects sunlight. Most of it is bathed in darkness. However, when the New Moon is close, an interesting phenomenon called “earthshine” occurs.
Earthshine is the dim glow of the Moon’s night side. It happens only a few nights before and after a New Moon or during the crescent phases.
During the crescent phases, the Earth, Moon, and Sun are almost aligned. In this position, the Earth’s disk appears to be nearly 100% sunlit as viewed from the Moon.
The Moon reflects this earthlight which causes its dark portion to have an ashen glow. This light illuminates the Moon much fainter because it has been reflected many times. The Earth reflects it from the Sun, then it is reflected by the Moon before it is seen from Earth as earthshine.
The earthshine event has been observed as early as the 16th century by no other than the famous Leonardo da Vinci. Because of this, it is also known as the “Da Vinci glow.”
Stargazing Under a Waning Crescent Moon
The Waning Crescent Moon is a good time for astronomy and night sky observations. During this phase, the illuminated portion of the Moon is constantly shrinking. As a result, the night is also getting darker.
Though it is not fully invisible like a New Moon, we get a relatively dark night during the Waning Crescent Moon. Another thing to consider is that it rises before sunrise and sets before sunset. In short, it is not up in the sky for most of the night.
Dark nights offer excellent stargazing opportunities. Since the Moon is not very bright, it will not drown out the less bright objects. This is a good time to spot stars, galaxies, nebulae, and other interesting deep sky objects.
Effect on the Sea and Tides
The gravitational pull of the Moon and Sun causes the changes of tides on Earth. But between the two, the tidal force of the Moon is stronger because it is much closer to us.
The position of the Sun, Moon, and Earth has effects on our tides. Therefore, knowing about the Moon phases will give us a better understanding of the changes our seas undergo.
When it comes to tides and Moon phases, the most important thing to remember are the primary phases. The Waning Crescent Moon and the other intermediate phases serve as transitions among these four main phases.
During the Waning Crescent phase, the tidal bulge is increasing as it will lead to the spring tides on the New Moon.
Spring Tides and Neap Tides
Spring Tides occur during New Moon and Full Moon. Since the Moon and Sun are aligned on both sides of the Earth, their gravitational pull is combined. This results in bigger differences in tide levels. High tides are very high and low tides are incredibly low.
Neap tides are the opposite of spring tides. It happens during the First Quarter and Last Quarter when the three bodies are at a right angle. With the Earth at the center, the gravitational pull of the Moon and Sun are canceled. As a result, there is a smaller tide range. High tides are relatively lower and low tides are relatively higher.
Symbols and Mythology
Moon symbol: 🌙
The Moon is often symbolized by the crescent shape. In mythology, many gods and goddesses are associated with the Moon. With that said, most of these deities are depicted with the crescent symbol.
In Greek mythology, the Moon is personified by the goddess Selene. While her brother, Helios, drives his chariot to bring in the Sun, Selene also flies her Moon chariot.
Waning Crescent Moon Dates for 2021 and 2022
The Waning Crescent Moon is just as exciting as the other phases of the Moon. It serves as a good time to spot amazing celestial objects. Below is the Waning Crescent Moon calendar for 2021 and 2022.
2021 | 2022 |
---|---|
January 7–12 | January 1 |
January 26–31 | |
February 5–10 | February 24–28 |
March 6–12 | March 1 |
March 26–31 | |
April 5–10 | April 24–29 |
May 4–10 | May 23–29 |
June 3–10 | June 21–27 |
July 2–8 | July 21–27 |
August 1–7 | August 20–26 |
August 31 | |
September 1–5 | September 18–24 |
September 29–30 | |
October 1–5 | October 18–24 |
October 29–31 | |
November 1–3 | November 17–22 |
November 28–30 | |
December 1–3 | December 17–22 |
December 27–31 |
Interesting Moon Facts
- Aside from earthshine and planetshine, there is also something called “ringshine.” As the name says, it is when the ring system of a planet reflects light from the Sun. In turn, this light gets reflected onto the night side of a planet or its moons. A common example of this is the Saturnian system.
- The brain is mostly made up of water (about 75%). Because of that, there is a belief that, like tides, the Moon phases have a profound effect on the brain. Called the “lunar effect,” some believe that the phases of the Moon influence the physiological aspects of a person.
- In Latin, the Moon is called Luna. This is the origin of the word “lunatic,” since it was believed that the Full Moon causes insanity to some.
- As you may have observed, there are only four moon phases in our calendars: New Moon, First Quarter, Full Moon, and Last Quarter. These are the Moon’s primary phases. The intermediate phases (Waxing Crescent, Waxing Gibbous, Waning Gibbous, and Waning Crescent) are not shown in our everyday calendars.
Frequently Asked Questions
1. What happens during a Waning Crescent Moon phase?
During a Waning Crescent phase, the Moon is less than a quarter away from completing an orbit around Earth. In this phase, the illuminated portion of the Moon is less than 50% and it keeps on shrinking until we cannot see it anymore.
When it does become invisible, it has completed the lunar cycle and is back at being a New Moon—the first phase.
2. What is the difference between a Waxing Crescent Moon and a Waning Crescent Moon?
The Waxing and Waning Crescent Moons have the same curve sickle shape. However, they have many differences.
Waxing Crescent Moon
- “Young Moon”
- Occurs after the New Moon
- The visible portion is increasing
- Illuminated portion based on observers’ location:
- Northern hemisphere: right side
- Southern hemisphere: left side
- Equator: Upper part (moonrise)/ Lower part (moonset)
Waning Crescent Moon
- “Old Moon”
- Occurs before the Full Moon
- The visible portion is decreasing
- Illuminated portion based on observers’ location:
- Northern hemisphere: left side
- Southern hemisphere: right side
- Equator: Lower part (moonrise)/ Upper part (moonset)
3. Is there an eclipse during the Waning Crescent phase?
There is no eclipse during the Waning Crescent phase. An eclipse only occurs when a shadow from one object falls on another.
This occurs on a New Moon (solar eclipse) and a Full Moon (lunar eclipse) when the three bodies are aligned. Still, an eclipse does not occur every month because of the tilt of the Moon’s orbit.
Sources:
https://en.wikipedia.org/wiki/Moon
https://moon.nasa.gov/moon-in-motion/moon-phases/
https://solarsystem.nasa.gov/moons/earths-moon/overview/
https://www.timeanddate.com/astronomy/moon/waning-crescent.html
https://en.wikipedia.org/wiki/Lunar_phase
https://www.almanac.com/astronomy/moon/calendar
Image Sources:
The Moon: https://upload.wikimedia.org/wikipedia/commons/9/9a/LROC_wac643nm_Moon_rotation268.gif
Waning Crescent Moon: https://moon.nasa.gov/internal_resources/361
Moon cycle: https://moon.nasa.gov/internal_resources/359
Which side of the moon can we see: https://storage.needpix.com/rsynced_images/-1368009476O7T.jpg
Venus and the Crescent Moon: https://cdn.pixabay.com/photo/2020/03/28/23/28/moon-4978859_1280.jpg
Earthshine: https://upload.wikimedia.org/wikipedia/commons/7/77/Croisant_de_lune_avec_sa_partie_%22noire%22.jpg
Stargazing: https://pixabay.com/photos/moon-sky-crescent-sunset-colorful-2682277/
Tides: https://cdn.pixabay.com/photo/2019/07/20/10/23/island-4350570_1280.jpg
Selene: https://upload.wikimedia.org/wikipedia/commons/thumb/8/8b/Diana-selene%2C_da_originale_ellenistico%2C_da_porta_s._sebastiano_02.JPG/800px-Diana-selene%2C_da_originale_ellenistico%2C_da_porta_s._sebastiano_02.JPG