The Mid-Autumn Festival is one of the most important holidays in Chinese culture. It is celebrated during the autumn equinox, when the moon is at its fullest and brightest at this time of the year. Moon-watching is an ancient tradition associated with this holiday. This year’s festival falls on Thursday, September 15th.
But for the first time in nearly 20 years, the festival will fall around the same time as a lunar eclipse. The astronomical event will occur between 1AM and 5AM on September 17th and will be a penumbral eclipse, meaning that Earth’s diffuse outer shadow will fall on the moon’s surface. It is a more subtle event than a total or partial eclipse, causing a slight dimming of the moon’s brightness.
The last time the Mid-Autumn Festival coincided with a lunar eclipse was September 17th, 1997, when a total lunar eclipse occurred. The next time will not be until September 29th, 2042.
As the eclipse is set to occur in the wee hours of the morning, it probably won’t disrupt normal moon-watching activities. However, another event is threatening to dampen the holiday – tropical cyclone Meranti, which has been gathering force in the Pacific Ocean, is moving toward Taiwan.
The storm is expected to intensify as it approaches land, becoming a super typhoon as it comes within 800 kilometers of Hong Kong on Wednesday. On Thursday, the storm is expected to come within 400 kilometers of the harbor city, before moving toward southeastern China.
Representatives of the Hong Kong Observatory report that it is possible that a typhoon signal will be hoisted on the day of the Mid-Autumn Festival, disrupting outdoor celebrations across the city.