ACROSS AMERICA — The rare Halloween blue moon Saturday offers a great way to celebrate in a fun, socially distanced way:
At moonrise, step outside and howl.
Start with some yelps. Then let loose with a full-voiced howl that will pierce the night air. This is actually a thing that has been happening across America.
Much like the balcony applause and singing in Italy and Spain, moon-howling in the United States emerged as a way to thank health care workers and other first responders, or simply as a way to blow off the stress of being cooped up.
Every month has a full moon, but the lunar cycle and calendar aren’t perfectly synced. They occur every 29.5 days when the moon is on the opposite side of the Earth and its face is fully illuminated by the sun. When a second full moon occurs in a single month — as is happening in October — it is called a blue moon.
It has nothing to do with the color of the moon, of course. You’ve no doubt heard the phrase “once in a blue moon,” which means something is rare and occurs very infrequently.
A blue moon on Halloween is even rarer. It’s not peculiar to 2020, though it would figure if it were. The last time a Halloween blue moon occurred everywhere in the United States was in 1944, and it won’t happen again until 2039, according to the Farmers’ Almanac.
Neither of the October full moons carries the supermoon designation. But as with the Oct. 1 full harvest moon, the Halloween blue hunter’s moon may seem to be more orange and larger over the horizon than other full moons.
The Old Farmer’s Almanac says that’s a “moon illusion,” explaining that “when the moon is low, it is viewed in relation to earthly objects, such as chimneys and trees, whose size and shape provide scale.”
The brain makes comparisons of the moon on the size of the other objects the eye sees, “and suddenly, the moon looks massive,” the Old Farmer's Almanac says.
Whatever full moon occurs closest to the autumnal equinox is known as a harvest moon because it provided light for farmers to get their crops out of the field before the advent of modern farming equipment with headlights. This year, the Oct. 1 full moon was a harvest moon.
When it’s not a harvest moon, the October full moon — and, this year, the Halloween blue moon — is known as a hunter’s moon because the moonlight helped hunters preparing for winter to see deer and other game animals in recently cleared fields.
It is sometimes referred to as the sanguine or blood moon, perhaps because of the blood associated with hunting, the Old Farmer’s Almanac says, but also possibly because it is associated with the brilliant colors of fall foliage.
Some other names for non-harvest October full moons are the “travel moon” or the “dying grass moon.”
The Halloween blue moon will interfere with watching for shooting stars from the long-running Taurid meteor shower. It runs annually from Sept 7 to Dec. 10, peaking around Nov. 4-5.
This shower isn't particularly prolific, producing about five to 10 meteors an hour at the peak. What makes the Taurids unusual is that the meteors come from separate debris streams — dust grains left behind Asteroid 2004 TG10 and debris from Comet 2P Encke. A first-quarter moon at the shower's peak may block out all but the brightest meteors. After midnight is the best time to look for meteors, which radiate from the constellation Taurus but can be seen anywhere in the sky.