The lunar phases (phases of the moon) are such an important part of our day to day (night to night) life that sometimes we don’t even notice it. We enjoy the full moon when we look up and see it. We learn about how the phases of the moon can affect the tides, or are told stories about the “Man in the Moon”, or listen to tales of werewolves changing with the full moon. At some point, however, we learn a bit more and notice more, notice the phases and colors.
The first time I saw a Lunar Eclipse and fell in love with astronomy
When I was a child, we lived on a small lake in the middle of rural Georgia. The sounds of the nighttime soothed me to sleep on many a night. I don’t recall ever being afraid of it. Nighttime fascinated me, and many nights I would sit outside on the dock down by the lake and stare up at the sky. There I would count stars, contemplate the moon, and always be ever-watchful for the elusive shooting star. Some nights, usually in the summer, my dad and I would take a canoe out to the middle of the lake to enjoy the sky. This was especially wonderful during lunar eclipses or meteor showers! It was also, much to my childlike surprise, a great way to learn about astronomy without it feeling like homework.
Nothing substitutes going out and observing the Lunar Phases of the Moon yourself, but it helps to have an idea of what you’re looking at. Over the next month, we’re going to talk about several phases of the moon as they happen in the Northern Hemisphere. It’s important to note, by the way, that this research is predominantly based upon western culture concepts. If you live in any of the other hemisphere your perspective and the dates are going to be different.
What are the basic lunar phases of the moon?
In the northern hemisphere the best known phases of the moon are the four principal phases: new moon, 1st quarter, full and 3rd quarter.
New Moon – this phase is when the moon is completely within Earth’s shadow
1st Quarter – this moon phase is when approximately 50% of the right side (viewed from Earth) of the disc [of the moon] is lit.
Full moon – when 100% of the moon’s disc is illuminated.
3rd Quarter – when 50% of the moon disc on the left side (as viewed from Earth) is lit.
These four principles of the lunar phases are distinguished by the differential of intervals between ecliptic longitude of the sun and that of the moon equaling 0°, 90°, 180°, and 270°. The ecliptic is the apparent path of the motion of the sun (or moon) as seen from the earth. In order to understand the difference between the longitude of the sun in relation to the longitude of the moon, you need to calculate the ecliptic longitude.
There are also four intermediate lunar phases.
These intermediate phases, the phases between the above quarters, are either crescent phases or gibbous phases.
Waxing Crescent – this is the phase between New moon and 1st Quarter. It is when the lit aspect of the moon seen from Earth is less than a quarter visible, but still visible.
Waxing Gibbous – this phase is between the 1st Quarter and Full Moon. The lit aspect of the moon seen from Earth is greater than a quarter on the right side, but not yet full.
Waning Gibbous – the phase between the Full Moon and the 3rd Quarter where the lit aspect of the moon seen from Earth is greater than a quarter on the left side, but not yet 50%/half visible.
Waning Crescent – this phase is between the 3rd Quarter and the next New Moon. It is when the lit aspect of the moon seen from Earth is less than a quarter visible to the left side, but not yet a New Moon.
The Lunar Calendar
The lunar phases have been the basis for tracking the passing of time in for well over 10,000 years, possibly even as far back as 17,000 years ago. Scholars have a theory that some caves near Lascaux, France could indicate hints of the use of a lunar calendar. The very first lunar calendar known for certain was in prehistoric Scotland. The first fully developed lunar calendar was developed by the Sumerians. Their ‘month’ began based upon the arrival of the visible moon.
Eventually, as astronomy and astrology evolved, it was realized that the time between a New Moon and Full Moon was variable. Depending upon where you were on the planet you saw the phases at different dates. These were seen as moderately inefficient. In particular, the seasons were really off. In 350 B.C.E the Greeks put in provisions (laws) that governed the coordination of the lunar and solar calendars.”
The Gregorian Calendar, used the most in the world today, was born from a lunar calendar. It eventually became a solar based calendar that we use today. Interestingly, one of the oldest lunar calendars still in use today is the Jewish Calendar.
From my Childhood amazement of the moon was born a great love of Astronomy.
When we were asked to write up something for The Researcher’s Gateway on the Lunar Phases, I can’t begin to describe my excitement. How wonderful would it be to share this love of my childhood? To present some information to the universe that might help other budding astronomers. To encourage them to learn and embrace their own love of the celestial beings in the sky.
We’re going to examine each phase a bit further over the next “lunar month” so that we can not only explore the phases, but add a bit of history and folklore to each one as we go. I hope that you all enjoy learning about the Lunar Phase (Phases of the Moon) as much as I enjoyed writing them up!
Keep your eyes to the sky and dream,
Galen
at The Researcher’s Gateway.
The November 2019 Phases of the Moon (Northern Hemisphere)
- New Moon – 27th October, 2019
- Waxing Crescent – 1st-3rd November, 2019
- 1st Quarter – 4th November, 2019
- Waxing Gibbus – 5th-11th November, 2019
- Full Moon – 12th November, 2019
- Waning Gibbus – 13th-120th November, 2019
- 3rd Quarter – 21st November, 2019
- Waning Crescent – 21st-25th November, 2019
