What is Phases of the Moon? | Types, Definition, Structure, Function & Facts

What is Phases of the Moon?

The moon itself does not emit light like the sun. What we see when we see the moon is sunlight reflected from the moon.

The period of the moon is the amount of moon that appears on Earth for us to be illuminated by the sun. Half of the moon is always illuminated by the sun, except during a solar eclipse, but only the visible part is illuminated. It is the phase of the moon.

About once a month, exactly every 29.53 days, the phases of the moon complete a full cycle. As the moon orbits the Earth, we can only see part of the illuminated side. When you can see 100% of the illuminated face, it’s a full moon. When we cannot see any bright side, it is called a black moon or new moon.

What are different Types of Moon Phases?

As the moon orbits or orbits the Earth, the phase changes. We’ll start with what’s known as the New Moon phase. This is where we cannot see any moon. The moon is between us and the sun (see photo). As the moon orbits the earth, we can see more and more bright sides until the moon is on the opposite side of the earth from the sun and we have a full moon. As the moon continues to orbit the Earth, we see less and less of the illuminated side.

The phases of the moon that begin with a New Moon are:

  • New Moon
  • Waxing Crescent
  • First Quarter
  • Waxing Gibbous
  • Full
  • Waning Gibbous
  • Third Quarter
  • Waning Crescent
  • Dark Moon

The New Moon and Dark Moon are almost the same phase occurring at almost the same time.

Waxing or Waning?

As the New Moon begins its orbit and we see more and more moons, it’s called Waxing. As the moon reaches its full cycle, we begin to see the moon less and less. This is called Waning.

Lunar Calendar

The lunar calendar is a calendar based on the orbit of the moon. A lunar month (29.53 days) is slightly shorter than an average standard month (30.44 days). If you only have 12 lunar months, you will have about 12 days less than a year. As a result, very few modern societies use lunar calendars or months. However, many ancient societies measured their time in terms of lunar months or “moons”.

Eclipse

A lunar eclipse occurs when the Earth is exactly between the Moon and the Sun, so none of the Sun’s rays can reach the Moon. A solar eclipse occurs when the moon precisely blocks the sun’s rays from reaching the Earth. A lunar eclipse can be seen from anywhere on the dark side of the Earth. Solar eclipses can only be seen from certain places on Earth because the moon only obscures the sun over a small area. Solar eclipses always occur during the new moon phase.