A blue moon refers to the appearance of two full moons in a single month, which is a rare occurrence that happens about every three years. Other less potent volcanos have turned the moon blue, too.
Astronomical Blue Moons happen either once every two to three years. One belief on the origin of the term “blue moon” is that “blue” is a corruption of the obsolete term “belewe” meaning to betray, with another full moon in a month being seen as somehow unnatural. The chemicals are the ones that make the the moon appear blue from Earth.
A Blue Moon will shine over Kent and Sussex this Friday, July 31. And then, oddly, two months later in March 2018, before waiting until October 2020.
The full moon rises at sunset and sets at sunrise, and while moon-gazing is wonderful for lovers, star-gazing is washed out and it’s even a poor time to look at the moon. According to modern folklore, the second full moon in a calendar month is known as a blue moon. So save a few minutes on Friday night to remember that it is one to be remembered and be optimistic, because it just might be the night of your life! When we have the privilege to see a moon of a different color, this is thanks to events happening on Earth and not in space. In 1883, the Indonesia’s Krakatoa volcano erupted at a force of a 100 megaton bomb, killing about 36,000 people, making it one of worst volcanic disasters ever. The ash cloud scattered red light, which meant the moon appeared blue or green. Forest fires can change the appearance of the sun and moon. Back to new moon: Twnenty-nine and a half days later, the moon is once again new and the whole cycle of phases, called the synodic month, starts all over again. Recent Canada forest fires, sending smoke into the atmosphere, have led to sightings of a red-orange sun and moon.
This is a wonderful time to start sky-watching with a telescope.