Unlike its name suggests, a blue moon is not named after the colour but instead refers to the second full moon in a calendar month.
Most months only have one full moon, therefore, a second is a rare event, occurring approximately once every two or three years.
It marks the first time in five years that two supermoons have appeared in the same month, a rarity astronomers don’t expect to see again until 2037.
The biggest and brightest Moon of the year was visible on Wednesday night.
The last time two full supermoons were seen in the same month was in 2018.
According to the United States National Aeronautics and Space Administration (NASA), about 25% of all full moons are supermoons and two super blue moons in January and March of 2037.
