Lunar phase

The lunar phase is the shape of the directly sunlit portion of the Moon as viewed from Earth.

Lunar phase refers to the shape of the directly sunlit portion of the Moon as viewed from Earth. The lunar phases change cyclically as the Moon orbits the Earth, according to the relative positions of the Earth, Moon, and Sun.

Phases of the Moon

The lunar cycle is approximately 29.5 days long, during which the Moon goes through several distinct phases:

New Moon

The New Moon occurs when the Moon is positioned between the Earth and the Sun. During this phase, the side of the Moon that is illuminated by the Sun is facing away from the Earth, making it invisible to observers on Earth.

Waxing Crescent

Following the New Moon, the Moon enters the Waxing Crescent phase. During this phase, a small sliver of the Moon becomes visible as a crescent shape, growing larger each night.

First Quarter

The First Quarter phase occurs when half of the Moon's surface is illuminated as seen from Earth. This phase is also known as a "half moon," and it occurs approximately one week after the New Moon.

Waxing Gibbous

The Waxing Gibbous phase follows the First Quarter. During this phase, more than half of the Moon is illuminated, and it continues to grow until it becomes a Full Moon.

Full Moon

The Full Moon occurs when the entire face of the Moon is illuminated by the Sun. This phase happens when the Earth is between the Sun and the Moon, allowing the full sunlit side of the Moon to be visible from Earth.

Waning Gibbous

After the Full Moon, the Moon enters the Waning Gibbous phase. During this phase, the amount of illumination decreases each night.

Last Quarter

The Last Quarter, or Third Quarter, phase occurs when half of the Moon's surface is again illuminated, but the opposite half compared to the First Quarter.

Waning Crescent

The Waning Crescent is the final phase before the cycle repeats with the New Moon. During this phase, only a small crescent of the Moon is visible, decreasing each night until the New Moon.

Causes of Lunar Phases

The lunar phases are caused by the changing angles of illumination by the Sun as the Moon orbits the Earth. The Moon does not emit its own light; it reflects the light of the Sun. As the Moon travels around the Earth, different portions of its surface are illuminated, creating the phases.

Cultural Significance

Throughout history, the lunar phases have held significant cultural and religious importance. Many calendars, such as the Islamic calendar, are based on the lunar cycle. The Full Moon is often associated with various festivals and rituals in different cultures.

Also see

• Eclipse
• Tide
• Lunar calendar
• Moon
• Sun