Last couple of items on Blue moons until 2015

Follow the link for the most thorough, detailed explanation for how the use of blue moon evolved from the third full moon in a quarter with four to the second full moon in a month. As it happens, August’s meets both definitions, but January 2018 won’t!

Blue moon: one small mistake, giant folklore for the sky – Capital Weather Gang – The Washington Post

The next blue moon occurs on July 31, 2015. We get two blue moons in 2018 when they fall within January and March. (Always deprived of days, February 2018 gets no respect and no full moon.)

Blue moon: one small mistake, giant folklore for the sky – Capital Weather Gang – The Washington Post

Blue moon and Sturgeon moon in August 2012 – Capital Weather Gang – The Washington Post by Blaine Friedlander

[H]anging out at the Astronomy Café, you can learn amazing things about blue moons. In 1999, you may recall we had two full moons in January and March. And February had no full moons at all.

In 2018, we’ll enjoy double blue moons again in January and March – and once again February is devoid of official lunar plump. Odenwald – the author of “The Astronomy Café,” “Back to The Astronomy Café,” and “Patterns in the Void” – explains on his website that the lunar month is 29.53 days long. The largest number of days in February is 29 days, so February will never see a blue moon.

Rare among the rare: Blue moons can occur in months with only 30 days – and that happened Nov. 30, 2001, Odenwald says. We have two more decades before that happens again on Sept. 30, 2031.

On many different levels, blue moons have a bright, festive future: Get your Halloween costume ready for the Oct. 31, 2020 and the Oct. 31, 2039 events. You can ring in 2029 with a blue moon on Dec. 31, 2028.

Blue moon and Sturgeon moon in August 2012 – Capital Weather Gang – The Washington Post

Watch Out for the Blue Moon – NASA Science

A truly-blue Moon usually requires a volcanic eruption. Back in 1883, for example, people saw blue moons almost every night after the Indonesian volcano Krakatoa exploded with the force of a 100-megaton nuclear bomb. Plumes of ash rose to the very top of Earth’s atmosphere, and the Moon … it turned blue!

Watch Out for the Blue Moon (plume, 200px)

Smoke from volcanoes and forest fires can cause the Moon to turn blue. [Blue Moon Stories]

Krakatoa’s ash was the reason. Some of the plumes were filled with particles 1 micron wide, about the same as the wavelength of red light.  Particles of this special size strongly scatter red light, while allowing blue light to pass through. Krakatoa’s clouds thus acted like a blue filter.

People also saw blue-colored Moons in 1983 after the eruption of the El Chichon volcano in Mexico. And there are reports of blue Moons caused by Mt. St. Helens in 1980 and Mount Pinatubo in 1991.

Certain forest fires can do the same trick.  A famous example is the giant muskeg fire of Sept. 1953 in Alberta, Canada.  Clouds of smoke containing micron-sized oil droplets produced lavender suns and blue Moons all the way from North America to England.

There are plenty of wildfires burning in the hot, dry USA this month.  If any of them produce smoke with an extra dose of micron-sized particles, the full Moon might really turn blue.

On the other hand, maybe it will turn red.  Often, when the moon is hanging low, it looks red for the same reason that sunsets are red.  The atmosphere is full of aerosols much smaller than the ones injected by volcanoes.  Measuring less than a micron in diameter, these aerosols scatter blue light, while leaving the red behind. For this reason, red Blue Moons are far more common than blue Blue Moons.

Watch Out for the Blue Moon – NASA Science