If you missed the conjunction between the almost full moon and the star Spica last month, here’s another chance to see it.
The chart shows the view looking south-west from London at 04.00 BST on the morning of 23 April. The moon will be full with 99.3% of its visible surface illuminated, and it will be passing very close to Spica, the brightest star in the constellation of Virgo.
Such conjunctions are frequent between these two celestial objects, because Spica itself sits very close to the ecliptic. This is the plane of the solar system, and so all the planets, the sun and the moon orbit along or close to this line in the sky. Thus, the moon passes Spica every month, sometime even passing in front of it.
Another bright star that is close to the ecliptic is Antares, the brightest star in Scorpius, the scorpion. It too is frequently close to the moon, and occasionally occulted by it. From the southern hemisphere, the moon and Spica will be visible in the north-western sky in the early hours of the morning, although they will not be quite so close to one another in the hours of local darkness.
