Starwatch: Jupiter, Saturn and Venus chart the moon’s movement

Jupiter and Saturn will showcase the moon’s phases with Venus providing additional markers along the way

starwatch 6/12/21

This week we can again take advantage of Jupiter and Saturn’s placement in the evening sky to chart the movement of the moon and the development of its phases. What makes it special is that Venus has joined the party to provide even more reference points along the way.

The chart shows the view looking south-west from London at 1630 GMT on 6 December. You should be able to see the planets relatively easily but the moon will present more of a challenge. Only 8% of its visible surface will be illuminated and you will need a clear south-western horizon to catch a glimpse.

The following night, things improve considerably. The moon will sit between Venus and Saturn and be 16% illuminated. On 7 December, it will have moved to between Jupiter and Saturn, and the illumination will be 25%. The night after it will be near Jupiter, with 35% Earth-facing hemisphere illumination. Venus will be the brightest, lowest planet, with Jupiter the second brightest but highest. You may have to look a bit harder for fainter Saturn in between. From the southern hemisphere, the groupings take place much higher in the western sky.