The full moon tomorrow is going to be an extraordinary combination of a ‘supermoon’  and a blue moon, Professor Chandana Jayaratne said. 

“As a result of the full moon occurring when the moon is at its closest to the Earth in its orbit, the moon will be  14% bigger and 30% brighter than some of the other full moons that we have seen in the past,” Professor Jayaratne said.  

“When the moon is full while it is near its closest approach to Earth, it is called a Super Full Moon or a Supermoon. On August 31, 2023 at 7.05 a.m., the moon will be closest to the Earth with a distance of 357,344 kms. It won’t get any closer to us until November 2025. The size and brightness of the full moons on poya days vary slightly from month to month because of the non-circular but elliptical shape of the moon’s orbit around the earth with the closest distance of the moon to the earth ("perigee") being about 50,000 kms closer than the furthest distance ("apogee"),” he added.

“When two full moons fall on the same month the second full moon is called the blue moon. This is just a name and the moon actually does not appear in blue. 

"Though one can see the full moon from 30th dusk after sun-set in the eastern skies, the best time to observe this super blue moon is on the 31st pre-dawn period before sunrise. Watch the western skies to see the big moon with ringed bright Saturn, which is at opposition these days, closer to the moon. If one misses this opportunity one will have to wait until January and March 2037 for the next super blue moons,” he also said. (Yohan Perera)