Blue Moon over Mabalingwe

Photoshop-induced Blue Moon

It was "Once in a Blue Moon" last night, Friday evening July 31, 2015. Astronomers call the second full Moon in a month with two full Moons a "Blue Moon."

The Moon was not however actually blue on Friday night. A Moon that actually looks blue is a very rare sight indeed. The Moon, full or any other phase, can appear blue when the atmosphere is filled with dust or smoke particles of a certain size; slightly wider than 0.7 micron. The particles scatter the red light making the Moon appear blue in color. This can happen for instance after a dust storm, forest fire or a volcanic eruption.

Eruptions like on Mt. Krakatoa, Indonesia (1883), El Chichon, Mexico (1983), Mt. St. Helens (1980) and Mount Pinatubo (1991) are all known to have caused blue-colored moons.

Vince and I were in Mabalingwe Nature Reserve in the Waterberg for the weekend and on Friday night we set up our tripod on the balcony of our thatched cottage in order to take some pictures of the Blue Moon through the trees.

 The next Blue Moon will be January 31, 2018. I wonder where we will be for that one!