The Sky This Week, 2012 October 2 – 9 — Naval Oceanography Portal

With sunrise in Washington now occurring after 7:00 am EDT many of us are being dazzled by the bright glimmer of Venus in the east as we gather the morning paper or walk the family dog. The planet shines at a blazing magnitude of -4.1, which is bright enough to cast shadows in very dark locations. You won’t see your shadow by the light of Venus this week since the Moon gives her fierce competition, but later this month you can try to spot this elusive sight.

The Sky This Week, 2012 October 2 – 9 — Naval Oceanography Portal

The Sky This Week, 2012 September 25 – October 2 — Naval Oceanography Portal

Full Moon occurs on the 29th at 11:19 pm Eastern daylight Time. Since this Full Moon occurs closest to the autumnal equinox it is almost universally known to Northern Hemisphere residents as the Harvest Moon. The name derives not only from the season but also from a curious quirk of orbital geometry. For viewers in mid to high northern latitudes the Moon seems to skip along the eastern horizon as it rises from night to night around the time of the full phase. In fact, at latitudes north of the Arctic Circle the Moon rises earlier on successive nights! For most of us, though, the difference in moonrise times is somewhere between 15 and 30 minutes for a few days around Full Moon, depending on latitude. Thus the effect is one where the light of the rising Moon adds to the light of twilight, enabling farmers to squeeze a little extra time into their harvest activities each day. Out of the many different names that sky lore ascribes to the year’s various Full Moons, the Harvest Moon is probably the most widely recognized by the general public, followed by next month’s Hunter’s Moon. Of course, in the Southern Hemisphere the opposite case applies; their "Harvest Moon" would fall near the vernal equinox in March.

The Sky This Week, 2012 September 25 – October 2 — Naval Oceanography Portal

The Sky This Week – 2012 September 18 – 25 — Naval Oceanography Portal

September 22nd has been designated as "International Observe The Moon Night", a special evening to look at and learn about our closest neighbor in space. …

The 22nd also happens to be the date of autumnal equinox, which occurs at 10:49 am EDT. At this time the Sun stands directly over the Earth’s equator just off the northeast coast of Brazil. Although the equinox officially marks the beginning of the astronomical season of autumn, the duration of night doesn’t exceed that of daylight until the 26th due to a combination of atmospheric refraction and the Sun’s apparent disc. However, it is one of the times of the year when the times of sunrise and sunset change most rapidly, so most of us will quickly notice the shortening days

The Sky This Week – 2012 September 18 – 25 — Naval Oceanography Portal

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!

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

The Sky This Week, 2012 August 27 – September 4 — Naval Oceanography Portal

The month’s second Full Moon occurs on August 31st at 9:58 am Eastern Daylight Time. The second Full Moon to fall in a calendar month has now become popularly known as a "Blue Moon", although skylore experts don’t necessarily agree on this. The term initially referred to the third Full Moon in a season with four Full Moons (normally there are three.) However, a misinterpretation of the 1937 "Maine Farmer’s Almanac" in a popular magazine in 1946 led to the current definition. Either way the event is comparatively rare, occurring seven times in a 19-year cycle. By either definition the "Blue Moon" resets the monthly calendar of popular Full Moon names, so the next one, which will occur on September 29th, will be the fabled "Harvest Moon".

The Sky This Week, 2012 August 27 – September 4 — Naval Oceanography Portal