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BAA Observing calendar

Full Moon - supermoon

Sunday, 2017, December 3 - 15:48

Dominic Ford – originally published on

The Moon will reach full phase – making it visible for much of the night, lying almost directly opposite the Sun in the sky.

This full moon will take place unusually close to the time of month when the Moon makes its closest approach to the Earth – called its perigee. This near coincidence between a full moon and lunar perigee will mean that this full moon will appear slightly larger and brighter than usual in the night sky. Full moons such as this are sometimes called supermoons, and occur roughly once every 13 months.

Full Moons are traditionally given names according to the season in which they fall, and this will be the third full moon of autumn 2017, traditionally called the Oak Moon.

Over the nights following 3 December, the Moon will rise around an hour later each day so as to become prominent later in the night. Within a few days, it will only be visible in the pre-dawn and early-morning sky. By the time it reaches last quarter, a week after full moon, it will rise at around midnight and set at around noon.

At the moment when the Moon reaches full phase, it will lie at a declination of +17°35' in the constellation Taurus, and so will appear highest in the northern hemisphere. It will be visible from all latitudes south of 62°S. Its distance from the Earth will be 357,000 km.

The exact position of the Moon at the time it reaches full phase will be:

Object Right Ascension Declination Constellation Angular Size
The Moon 04h42m10s +17°35' Taurus 33'21"

The coordinates above are given in J2000.0.

The details of this observing event were provided courtesy of