Hongkongers will get to see a total lunar eclipse on Saturday, as long as the weather is clear.
The main action will start at around 7.54pm and end at 8.06pm. It is part of a series of four total lunar eclipses, an astronomical event known as a tetrad. The first lunar eclipse in the tetrad happened on April 15 last year. The second one was on October 8 and the final one - which will not be visible in the city, unfortunately - will occur on September 28.
Astronomy lovers will have to wait another 17 years if they miss this tetrad, as the next one will not occur until 2032.
The moon will appear dull red in colour, but will not completely vanish during the eclipse.
The phenomenon happens because the Earth's atmosphere scatters the blue part of sunlight and the remaining red light is refracted onto the moon. If the weather is clear enough, the event will be visible in eastern and southeastern parts of Hong Kong, such as Shek O, the east dam of High Island Reservoir and the top of Tai Mo Shan.
If you want to watch the eclipse with some friends, the Space Museum will organise a free observation activity along the middle section of the Avenue of Stars in Tsim Sha Tsui from 6.45pm on Saturday. Museum staff will have telescopes for people to use.
If you are too busy to make it outside, the Hong Kong Observatory will also provide a webcast of the event, from moonrise until the moon leaves the penumbra (the Earth's shadow), on its website.