Starwatch: Venus, Spica and a crescent moon meet at dawn


There is a beautiful triple meeting in the dawn sky this week. The brilliant “morning star” of Venus is close to Spica, the brightest star of Virgo, the virgin. On the mornings of 8 and 9 December, the already pretty pairing will be joined by a thin waning crescent moon.

On 8 December, the moon will be closest to Spica and will have 22% of its visible surface illuminated. A day later, the moon will be closer to Venus and its illuminated portion will have shrunk to just 14%.

The chart shows the view looking south-east from London at 07:00 GMT on 9 December. The sky will already be beginning to lighten but the sun will not rise for another 53 minutes. Venus is brilliantly bright at magnitude –4.1, much brighter than any star and outshone only by the moon and the sun. The moon is in the last week of its current lunation, or lunar month, and is heading towards the sun. With each successive day, its illuminated portion grows smaller and it rises a little later. As the week progresses, the moon will appear to move closer to the sun until it is lost in the daylight glare. The conjunction is also visible in the east before dawn from the southern hemisphere.