Witches and ghost and coffins are all part of the scary stargazing side of Halloween, as well as lots of spacey costumes to choose: from Star Wars to Star Trek; an alien to a real astronaut.
You might not know that Halloween is an astronomical holiday. And it’s not just the things that go bump in the night, and astronomers certainly aren’t afraid of that! In our telescopes we can see some pretty scary sights like the Flaming Head Nebula, the Zombie Eye, and lots of galactic ghosts!
Despite all the horrible fun, Halloween is tied into the astronomical calendar. The celebration goes back to the Druids and other ancient clans of medieval Europe. They marked the seasons of time in “cross-quarter” days.
A cross-quarter day in our calendar of seasons is that time between a Solstice and Equinox. Everyone is of course familiar with the Winter and Summer solstices and the Spring and Autumn equinoxes. Halfway between the Winter Solstice, around Dec. 22, and Spring Equinox, around March 22, is Ground Hog Day, on Feb. 2. Between that first day of Spring and the Summer solstice is May Day on the 1st; between the first day of Summer and the Autumnal Equinox is Lammas Day on Aug. 1st; and between the first day of the Fall season and first day of Winter Solstice is Halloween on Oct. 31st.
These eight benchmarks in our 365-day calendar are established in many iconic landmarks from civilizations around the world, including the famous Stonehenge in England. How and why they are celebrated sometimes goes so far back into human history that the rituals are enshrouded in mystery.
Ground Hog Day came from the observation of animals stirring in mid-winter, a hopeful sign of warmer days. And along the way came the celebrated furry critter named Punxsutawney Phil in Pennsylvania. May Day simply praised the beauty and rejuvenation of life on Mother Earth—it used to be a school yard celebration with outdoor games and dancing while wrapping streamers around a “May pole.”
Many of us have never heard of “Lammas Day,” a cross-quarter day between Summer and Autumn. It comes from the Anglo-Saxon language and a word that translates into “loaf,” so it is Loafmas, celebrating the first harvest of wheat in the beginning of August. Tradition in European countries have loaves of bread with the new wheat brought to churches and markets for a celebration of the impending harvest. There is also a pagan connection to Lammas Day.
The best known of the cross-quarter days is Halloween. Its religious roots are the Christian “All Saints Day” or Day of the Dead, on Nov. 1st, where the names of the departed loved ones are written down and praised in a ceremony. The day before is a focus of the human spirit leaving the living world—and everyone is familiar with the sometimes over-the-top macabre celebration. Halloween, in fact, has become the second largest consumer holiday behind Christmas.
And images of those spooks and goblins are fun to find in the nebulae, galaxies and stellar formations astronomers hunt down in their telescopes. Some we can see in a backyard telescope, like the Ghost of Jupiter exploded star (a planetary nebula), or the vast Ghost Nebula imaged by the great Hubble Space Telescope.
Like puffy clouds in our earthly atmosphere on a beautiful day, the human mind can see familiar shapes of people and animals. The same applies to the often-odd shapes of interstellar objects.
So, on Halloween astronomers love to tout the celestial wonders of the Witch Head Nebula and the Frankenstein Galaxy. There’s the Coffin Nebula and the Out of Body nebulous cloud. Even a Death Eater Nebula that looks like it’s from a Harry Potter movie.
And then there is the “Demon Star” that is easy to see with your naked eye on Autumn nights. This is the variable star called Algol, easy to find in the constellation Perseus the Hero, below the recognizable “M” shape of Cassiopeia the Queen. Algol is famous because it changes its brightness by a noticeable full magnitude of stellar brightness during a three-day period. The star also is the one mythology places as the head of the ugly Gorgon called Medusa—who’s gaze turns humans to stone. Perseus cut her head off, and it dangles from his arm in the form of the Demon Star, Algol.
Finally, we can’t ignore the Moon and its spooky connection to Halloween. Where would a Werewolf be without the light of the Full Moon. And how about that rare, “Blood Moon” when Dracula seeks his victims for eternity?
Everytime the Moon is at full phase it seems there is some lunacy—just ask health care and first response workers. But lycanthropy? Leave that hairy man-wolf stuff to Hollywood.
It is the Blood Red Moon that created fear and mystery into the ancient stargazers for its rarity and length. And spawned a cult of Dracula lovers, the bat creature who morphs into a human vampire craving blood and promising an eternity of life, shunning daylight.
Today we know the Blood Moon is really a total eclipse of the Moon. It is when the Moon travels through the Earth’s shadow cast into space. These happen only at Full Moon and seen a couple times a year from specific, world locations. When in totality for 40 minutes or so, the Moon can visually look from deep red to copper in color. The pollutants in the Earth’s atmosphere disperse moonlight into the long visual wavelengths of orange to red.
The next total lunar eclipse seen in North America will be the night of Jan. 20/21, 2019. But ancient stargazers didn’t have a clue to the science, and the Blood Red Moon was a fearful sight. And a symbolic sight for Dracula, one of the horrific characters of Halloween.
Scary astronomy is a fun way to get people looking up at the stars and all the elements of the Universe. You’ll find that science fact far outshines anything that can be thought up in Halloween fiction.