Total lunar eclipse in Hong Kong on May 26
10 May 2021
The public will have an opportunity to observe a total lunar eclipse on May 26 (Wednesday), the same day when the biggest full moon of the year (viz. the “Super Moon”) appears. The diameter of the moon on that day will be about seven per cent larger than the ordinary full moon.
The coming total lunar eclipse will begin before moonrise. As the elevation of the Moon will be rather low during the eclipse, the event can be best observed at places with an unobstructed view to the southeast if weather permits. Details of the total lunar eclipse are as follows:
| Date | Time | Phenomenon | Elevation | Direction (Azimuth) |
| May 26 (Wednesday) |
6.56pm | Moonrise | -1 degree | East-southeast (113 degrees) |
| 7.01pm | Sunset | -1 degree | West-northwest (293 degrees) |
|
| 7.09pm | Total eclipse begins | 2 degrees | East-southeast (114 degrees) |
|
| 7.19pm | Maximum eclipse | 4 degrees | East-southeast (115 degrees) |
|
| 7.28pm | Total eclipse ends | 6 degrees | East-southeast (116 degrees) |
|
| 8.53pm | Moon leaves umbra | 22 degrees | Southeast (126 degrees) |
|
| 9.52pm | Moon leaves penumbra | 31 degrees | Southeast (136 degrees) |
The total lunar eclipse will begin at 7.09pm on that day and end at 7.28pm, with the maximum eclipse occurring at 7.19pm. During the period, the Moon will not completely vanish but will appear in dull red. This is the result of the blue part of sunlight being scattered away by the Earth’s atmosphere and the remaining red light refracted onto the Moon.
Members of the public can watch the lunar eclipse event via a webcast to be jointly provided by the Hong Kong Observatory, the Hong Kong Space Museum, the Ho Koon Nature Education cum Astronomical Centre (sponsored by Sik Sik Yuen) and the Po Leung Kuk Ngan Po Ling College.
For the latest weather conditions and the astronomical observation conditions on May 26, please refer to the 9-day Weather Forecast issued by the Hong Kong Observatory and the Weather Information for Astronomical Observation webpage.
The next lunar eclipse observable in Hong Kong will be a partial lunar eclipse on November 19, 2021.
Figure 1 The total lunar eclipse process on May 26, 2021
Figure 2 Schematic diagram showing elevation and azimuth of the Moon during the total eclipse on May 26, 2021