This week it is the almost full moon’s turn to closely match the star Spica.
The chart shows the view looking south-east from London at 22:00 GMT on March 26 – the time when the celestial conjunction will rise. The moon became full on March 24, but it still illuminated 97.5% of its visible surface as it passed Spica.
The star itself is the brightest in the constellation Virgo, the Virgin. It is located about 250 light years away and holds more than seven times the mass of the Sun. This gives it a luminosity of about 12,000 times that of our star and a radius seven and a half times greater.
For the ancient Egyptians, Spica was associated with the sky goddess Hathor. A temple at Thebes, built in 3200 BC, was aligned with the star. However, because the Earth’s axis of rotation gradually follows a circle in the sky, taking about 26,000 years to complete a full turn, the star is no longer aligned with the temple.
In the UK, clocks go forward one hour to British Summer Time on March 31.
