Hongkongers will be able to view an unusually long lunar eclipse in the early hours of Saturday morning.

“The eclipse will begin at 1.13am, with the stage of total eclipse lasting for 1 hour and 44 minutes, the longest duration since 2000,” the Observatory said. “The event will be visible at most places with an unobstructed view to the southwest till moonset at 6am.”

Lunar eclipse Hong Kong July 2018
Photo: Hong Kong Observatory.

A total lunar eclipse happens when the moon passes directly behind the Earth’s shadow. During the event, the Earth completely blocks sunlight from reaching the moon and gives the satellite a reddish colour – otherwise known as a “blood” moon. The average duration of a total lunar eclipse is around 50 minutes.

An almost two hour-long eclipse is rare; it is caused by the moon reaching its furthest point from the Earth and decelerating in its orbit. This will also result in a full moon that is the smallest of 2018.

Members of the public can attend a viewing event held by the Ho Koon Nature Education cum Astronomical Centre in Tseun Wan from 8pm on Friday to 6am on Saturday.

Alternatively, they can watch the eclipse on the Hong Kong Observatory’s website.

Hong Kong Observatory lunar eclipse 2018
Photo: Hong Kong Observatory.

The event is preceded by a Mars perihelic opposition at 7.18pm on Friday evening, where Mars, the Earth and the Sun lie on a straight line. The red planet will then appear brighter than usual to the naked eye. The last opposition took place in 2003 and it occurs every 15 or 17 years.

The next lunar eclipse will occur on July 17, 2019.

Jennifer Creery is a Hong Kong-born British journalist, interested in minority rights and urban planning. She holds a BA in English at King's College London and has studied Mandarin at National Taiwan University.