To the surprise of many, Halloween is a significant day on the astronomical calendar. Halloween is a cross-quarter day which means it falls approximately half way between the Autumnal Equinox, the astronomical start of fall and Winter Solstice, the astronomical start of winter.
Halloween’s origins date back to the ancient Celtic festival of Samhain (pronounced sow-in). The Celts, who’s history dates back 4,000 years, once had an empire that stretched from the Ankara region of Turkey in the east, across central Europe, into the Iberian Peninsula and Great Britain and Ireland in the west, celebrated their new year on November 1st.
This day marked the end of summer and the harvest and the beginning of the dark, cold winter, a time of year that was often associated with human death. Celts believed that on the night before the new year, the boundary between the worlds of the living and the dead became blurred. On the night of October 31 they celebrated Samhain, when it was believed that the ghosts of the dead returned to earth. To commemorate the event, Druids built huge sacred bonfires, where the people gathered to burn crops and animals as sacrifices to the Celtic deities. In addition to causing trouble and damaging crops, Celts thought that the presence of the otherworldly spirits made it easier for the Druids, or Celtic priests, to make predictions about the future. For a people entirely dependent on the volatile natural world, these prophecies were an important source of comfort and direction during the long, dark winter.
Samhain was also the day when the herders led the cattle and sheep down from their summer hillside pastures to the shelter of stable and byre. The hay that would feed them during the winter must be stored in sturdy thatched ricks, tied down securely against storms. All of the harvest must be gathered in — barley, oats, wheat, turnips, and apples — for come November, the faeries would blast every growing plant with their breath, blighting any nuts and berries remaining on the hedgerows. Peat and wood for winter fires were stacked high by the hearth. It was a joyous time of family reunion, when all members of the household worked together baking, salting meat, and making preserves for the winter feasts to come. The endless horizons of summer gave way to a warm, dim and often smoky room; the symphony of summer sounds was replaced by a counterpoint of voices, young and old, human and animal.
During the celebration, the Celts wore costumes, typically consisting of animal heads and skins, and attempted to tell each other’s fortunes. When the celebration was over, they re-lit their hearth fires, which they had extinguished earlier that evening, from the sacred bonfire to help protect them during the coming winter.
By A.D. 43, Romans had conquered the majority of Celtic territory. In the course of the four hundred years that they ruled the Celtic lands, two festivals of Roman origin were combined with the traditional Celtic celebration of Samhain.
The first festival was Feralia, a day in late October when the Romans traditionally commemorated the passing of the dead. The second festival was a day to honor Pomona, the Roman goddess of fruit and trees. The symbol of Pomona is the apple and the incorporation of this celebration into Samhain probably explains the tradition of “bobbing” for apples that is practiced today on Halloween.
By the 800s, the influence of Christianity had spread to the Celtic lands. In the seventh century, Pope Boniface IV designated November 1 as All Saints’ Day, a time to honor saints and martyrs. It is widely believed today that the pope was attempting to replace the Celtic festival of the dead with a related, but church-sanctioned holiday. The celebration was also called All-hallows or All-hallowmas (from Middle English Alholowmesse meaning All Saints’ Day) and the night before it, the night of Samhain, began to be called All-hallows Eve and, eventually, Halloween. Even later, in 1000 A.D., the church would make November 2 All Souls’ Day, also known here as Dia De Los Muertos, a day to honor the dead. It was celebrated similarly to Samhain, with big bonfires, parades, and dressing up in costumes as saints, angels, and devils. Together, the three celebrations, the eve of All Saints’, All Saints’, and All Souls’, were called Hallowmas.
What dark forms lurk in the mists of the Carina Nebula? These ominous figures are actually molecular clouds, knots of molecular gas and dust so thick they have become opaque.[img src=http://sanantonioskywatch.com/wp-content/flagallery/boo-tiful-skies/thumbs/thumbs_flaming-skull-of-perseus-perseus-a-in-x-ray.jpg]780The Flaming Skull of Perseus
Is this the head of Ghost Rider or is it something more ominous? <br /><br />This is an X-Ray image of the core of Perseus A, a giant galaxy that is a strong radio source. The image was taken by the Chandra X-Ray Observatory. The galaxy lies between the "eyes".[img src=http://sanantonioskywatch.com/wp-content/flagallery/boo-tiful-skies/thumbs/thumbs_ghost-nebula-ic-349.jpg]930The Ghost Nebula
NASA's Hubble Space Telescope has caught the eerie, wispy tendrils of a dark interstellar cloud being destroyed by the passage of one of the brightest stars in the Pleiades star cluster. Like a flashlight beam shining off the wall of a cave, the star is reflecting light off the surface of pitch black clouds of cold gas laced with dust. These are called reflection nebulae.[img src=http://sanantonioskywatch.com/wp-content/flagallery/boo-tiful-skies/thumbs/thumbs_ghost-of-neptune-abell-39.jpg]1310The Ghost of Neptune
This classic planetary nebula in Hercules resembles a ghostly planet Neptune.[img src=http://sanantonioskywatch.com/wp-content/flagallery/boo-tiful-skies/thumbs/thumbs_glowing-eye-nebula-ngc6751.jpg]1150Glowing Eye Nebula
Some have called this planetary nebula "God's Eye".<br /><br />Glowing in the constellation Aquila, the nebula is a cloud of gas ejected several thousand years ago from the hot star visible in its center. Planetary nebulae have nothing to do with planets. They are shells of gas thrown off by Sun-like stars nearing the ends of their lives. The star's loss of its outer, gaseous layers exposes the hot stellar core, whose strong ultraviolet radiation then causes the ejected gas to fluoresce as the planetary nebula.[img src=http://sanantonioskywatch.com/wp-content/flagallery/boo-tiful-skies/thumbs/thumbs_halo-of-the-cats-eye-nebula-ngc6543.jpg]830Cat's Eye Nebula
When show with it's halo, the Cat's Eye Nebula is even more eerie, more resembling the eye of some gargantuan feline[img src=http://sanantonioskywatch.com/wp-content/flagallery/boo-tiful-skies/thumbs/thumbs_little-ghost-nebula-ngc6369.jpg]490The Little Ghost
This little orb lies in Ophiuchus and taunts astronomers with its faint appearance.<br /><br />NGC6369 is a fifteen hundred year old planetary nebula that is the remains of a star that was once comparable to our own Sun in mass.[img src=http://sanantonioskywatch.com/wp-content/flagallery/boo-tiful-skies/thumbs/thumbs_ngc-2467.jpg]370Somebody is Watching You!
A large cloud of gas surrounds two clusters of stars that seem to be watching you, glaring at you.<br /><br />This is the star forming cloud NGC2467. Each eye is, in reality, a cluster of stars which are blowing holes in the gas cloud giving the appearance of a pair of eyes who's glare burns right through to your core.[img src=http://sanantonioskywatch.com/wp-content/flagallery/boo-tiful-skies/thumbs/thumbs_running-ghost-nebula-ic2118.jpg]430The Running Ghost Nebula
What could frighten a ghost? Whatever it was, it sent this guy flying across the cosmos.<br /><br />If this nebula looks familiar, it should, in a twisted way. It is actually the Witch Head Nebula rotated 90 degrees.[img src=http://sanantonioskywatch.com/wp-content/flagallery/boo-tiful-skies/thumbs/thumbs_screaming-monkey-nebula-dr-6.jpg]250Screaming Monkey in the Sky
In this Spitzer Space Telescope infrared image of DR 6, a star forming cloud containing about a dozen nascent stars. The wind from these stars are blowing the cloud away from them forming the eyes and the mouth of the Screaming Monkey[img src=http://sanantonioskywatch.com/wp-content/flagallery/boo-tiful-skies/thumbs/thumbs_sh2_136.jpg]190SH2-136
In space no one can hear you scream! I'm not sure what it is on the right that's chasing those two poor, terrified people running away with their arms up in the air, but it must be really frightening.[img src=http://sanantonioskywatch.com/wp-content/flagallery/boo-tiful-skies/thumbs/thumbs_tarantula-nebula-ngc2070.jpg]180Tarantulas in the Sky
This giant spider hangs ominously in the night sky in the Large Magellanic Cloud in Doradus [img src=http://sanantonioskywatch.com/wp-content/flagallery/boo-tiful-skies/thumbs/thumbs_the-brilliant-star-vfts-682-in-the-large-magellanic-cloud.jpg]180The Demon Nebula
This demonic looking nebula is a molecular cloud and star forming region at the core of the Tarantula Nebula.<br /><br />In this image is VFTS 682, one of the largest stars known at 150 solar masses lies near the center of the image.. It is unusual not because of its mass, but because it is a solitary star. R136, a super star cluster with a mass of 450,000 solar masses lies in the bottom center of the image. One of its stars R136a1, the most massive star found to date, weighs in at 265 solar masses.[img src=http://sanantonioskywatch.com/wp-content/flagallery/boo-tiful-skies/thumbs/thumbs_witch-head-nebula-ic2118.jpg]280The Witch's Head
Just off to the left of the knee of Orion which is marked by the bright star Rigel is the large glowing Witch Head nebula, which really does look like a classic depiction of a hag's face: open-mouth, scraggly nose, deep eyes, gaping as she looks off to the right. [img src=http://sanantonioskywatch.com/wp-content/flagallery/boo-tiful-skies/thumbs/thumbs_ghost-head-nebula-ngc2080_0.jpg]160The Ghost Head
This strange entity<br />The 'Ghost Head Nebula' is one of a chain of star-forming regions lying south of the 30 Doradus nebula in the Large Magellanic Cloud.<br /><br />Two bright regions (the 'eyes of the ghost'), named A1 (left) and A2 (right), are very hot, glowing `blobs' of hydrogen and oxygen. The bubble in A1 is produced by the hot, intense radiation and powerful stellar wind from a single massive star. A2 has a more complex appearance due to the presence of more dust, and it contains several hidden, massive stars. The massive stars in A1 and A2 must have formed within the last 10 000 years since their natal gas shrouds are not yet disrupted by the powerful radiation of the newly born stars. [img src=http://sanantonioskywatch.com/wp-content/flagallery/boo-tiful-skies/thumbs/thumbs_skull-nebula-w5-cesar-cantu_0.jpg]210The Skull Nebula
Glowing eerily green and yellow in this picture, the nebula W5 - nicknamed the Soul Nebula - peers into your soul with its black eye sockets filled with pinprick stars...<br /><br />In reality it's a large cloud of gas furiously churning out stars. The winds of subatomic particles and fierce light from those newborn stars carve out cavities in the gas, leaving what look like eye sockets and a nasal bone in a huge green skull.<br /><br />Image credit: César Cantú[img src=http://sanantonioskywatch.com/wp-content/flagallery/boo-tiful-skies/thumbs/thumbs_ic1340mrzonalunar950.jpg]90A Spectre in the Eastern Veil
Frightening forms and scary faces are a mark of the Halloween season. They also haunt this cosmic close-up of the eastern Veil Nebula. The Veil Nebula itself is a large supernova remnant, the expanding debris cloud from the death explosion of a massive star. While the Veil is roughly circular in shape covering nearly 3 degrees on the sky in the constellation Cygnus, this portion of the eastern Veil spans only 1/2 degree, about the apparent size of the Moon. That translates to 12 light-years at the Veil's reassuring estimated distance of 1,400 light-years from planet Earth. In the composite of image data recorded through narrow band filters, emission from hydrogen atoms in the remnant is shown in red with strong emission from oxygen atoms in blue-green hues.
The Legend of Jack-O’-Lantern
The Irish brought Jack-O’-Lantern to America. Jack was a legendary, stingy drunkard. He tricked the Devil into climbing an apple tree for a juicy apple and then quickly cut the sign of the cross into the tree trunk, preventing the Devil from coming down. Jack made the Devil swear that he wouldn’t come after his soul in any way. The Devil promised. However, this did not prevent Jack from dying. When he arrived at the gates of heaven, he was turned away because he was a stingy, mean drunk. Desperate for a resting place, he went to the Devil. The Devil, true to his word, turned him away. “But where can I go?” plead Jack. “Back where you come from,” spoke the Devil. The night was dark and the way was long, and the Devil tossed him a lighted coal from the fire of Hell. Jack, who was eating a turnip at the time, placed the coal inside and used it to light his way. Since that day, he has traveled the world over with his Jack-O’-Lantern in search of a place to rest. Irish children carved out turnips and potatoes to light the night on Halloween. When the Irish came to America in great numbers in the 1840s, they found that a pumpkin made an even better lantern, and so this “American” tradition came to be.
The Great Galaxy in Andromeda
By the end of evening twilight at this time of year the Great Galaxy in Andromeda, also know as M31, is well placed for observing. With no interfering moonlight, a fine opportunity is awaiting skywatchers in dark locations. Use the Great Square of Pegasus as a starting point. This “sky mark,” now rotated into a diamond shape, sits more than halfway up in the east. Sight across the diamond from the upper left corner star, β Pegasi or Scheat, to the lower left corner star, α Andromedae or Alpheratz, formerly known as δ Pegasi. Continue in that same general direction you will find a 3rd magnitude star called δ Andromedae. Take a slightly more northern course to 2nd magnitude β Andromedae or Mirach, lying about 8° to the northeast of δ Andromedae. Make a 90° turn to the right and move about 3½°. You are now at μ Andromedae, a 4th magnitude star. Making a slight course adjustment to the left and moving about 3° you will come to 5th magnitude ν Andromedae. Now slowly scan the area with a good pair of binoculars. You are looking for a faint oval glow, about 1½° to the southwest, that easily fits in the binocular field of view.