Venus will disappear behind the moon for about an hour on 9 November for viewers in several parts of the world. Here is what these lunar occultations are and how and when to watch this one happen.
What is the lunar occultation of Venus?
On 9 November, the moon will pass between Earth and Venus, making the latter disappear behind the moon for about an hour, before it reappears on the other side. This phenomenon, known as a lunar occultation of Venus, will be visible from most of Europe, the western part of Russia, as well as Greenland and some of northern Africa and western Asia. For everyone else, the two bodies will just pass close by each other.
What time is it happening?
In areas where you can see the occultation, it will happen during the daytime, but exactly when will vary depending on where you are. In London, it is due to begin around 9.45 am, around 10.50 am local time in Paris and around 10.26 am in Tromsø in Norway, for example. Use software like Stellarium or websites like In The Sky to check exactly when the occultation will start in your location.
How to see this event
The best way to view it is to find Venus about 20 minutes before the time the occultation will start. The planet will be near the moon, which will be a small crescent, just 15 per cent illuminated. Venus will be just below the moon and to the left.
Because it is during the day, it might be easier to find Venus using binoculars or a small telescope. But remember, whenever using such devices in the daytime, be sure not to look anywhere near the sun.
Once you have found the planet, you can watch as it moves towards the moon and, eventually, passes behind it. About an hour later, Venus will reappear on the other side of the moon, slightly higher in the sky than when it disappeared.
When will the next lunar occultation of Venus happen?
They are rare, and each one is only visible from certain parts of the world. This is because the moon appears in a slightly different part of the sky depending on where you are on Earth, because of a phenomenon called parallax.
The next lunar occultation of Venus will be in April 2024, chiefly visible from parts of North America. It will be visible again from Europe in September 2025.
The earliest recorded lunar occultation of Venus was in July 1476, by Abraham Zacuto, a medieval polymath who worked as the astronomer royal for the king of Portugal at the time.