Riyadh: The Arab world's skies witnessed yesterday, Sunday, the full moon of Dhu Al-Hijjah, which remained visible throughout the night until it set at sunrise on Monday, being the second full moon in May in the Gregorian calendar and known as a 'Blue Moon.'

According to Saudi Press Agency, Jeddah Astronomy Society (JAS) Director Majed Abu Zahra explained that despite the widespread use of the term 'Blue Moon,' it is not a scientific astronomical term but rather a calendrical description for an additional full moon within a given period. It is commonly used today to refer to the second full moon in a single Gregorian month, a definition that gained popularity during the 20th century.

He noted that a full moon occurs when the Moon is in opposition to the Sun relative to Earth, with its facing side fully illuminated, at the moment when the Sun-Earth-Moon angle reaches approximately 180 degrees.