What is the waxing gibbous moon?

The Moon goes through various stages in a month, one of which is the Waxing Gibbous phase, which starts right after the First Quarter stage.

The Moon phase, also known as a lunar phase, is the shape of the Moon’s directly sunlit portion as seen from earth. It is important to note that these phases gradually change over a month, as the Moon’s orbital positions around Earth, and Earth around the Sun, shift.

© NASA’s Scientific Visualization Studio

The observable side of the moon is sunlit, but it depends on the position of the Moon in its orbit. The Moon’s sunlit portion can thus vary from zero percent to 100 percent. It is important to note that the Moon has four principal phases: the New Moon, First Quarter, Full Moon and Last Quarter.

However, during the intervals between the principal phases are the intermediate phases. In these phases, the Moon’s apparent shape is either gibbous or crescent. The intermediate phases usually occur for seven days.

The term waxing is used to describe an intermediate phase when the Moon’s apparent shape is thickening. In other words, it is growing from a new Moon to a full Moon, while the term waning is used when the Moon’s shape is decreasing.

The Moon thus features four distinct intermediate phases: The Waning Crescent, The Waning Gibbous, The Waxing Gibbous and The Waxing Crescent. The Waxing Gibbous starts right after the first quarter phase, when the illumination is at 50 percent.

People will normally see a Waxing Gibbous Moon in the afternoon or shortly after moonrise, while it is ascending. However, it is quite common to discover a Waxing Gibbous Moon during the day, as at this phase of the Moon, as a fraction of the Moon’s dayside faces towards Earth.

It is believed that people will be able to view a Waxing Gibbous Moon from 13 November 2021 to 17 November 2021. Additionally, players can see it between 13 December 2021 and 17 December 2021.

© NASA/JPL-Caltech