Caoimhín's Content

We’re back to looking at the sky as it is right now. We are technically looking into next month, but that’s mostly just to keep the Moon out of the way. We’ll be starting in the city, light pollution on its own will already obscure enough stars, the Full Moon would make things even more difficult to see. We already touched briefly on the constellations and asterisms in an early video looking into November. The asterism of the Summer Triangle has moved to the west, bringing the square of Pegasus into the south just after sunset.

The square of Pegasus is itself an asterism, just a part of the constellation of Pegasus the Flying Horse. Showing the lines between the stars is the first step in seeing the constellations as they should be, and the constellation of Pegasus seems particularly big. This is one of the rare occasions where two constellations blend together. Pegasus and Andromeda both share the star Alpheratz, making them appear to be one big constellation. Andromeda can otherwise be a little tough to spot, but it is connected to the much easier to see square of Pegasus.

The W shape of Cassiopeia the Queen is also reasonably recognizable and visible in the city. The King Cepheus is a little fainter, but has a distinct shape, a triangle sticking out from a square, very similar to the classic kids drawing of a house, just above Cassiopeia. Just below Cassiopeia is the hero Perseus, making a fin shape. Some of the stars in Perseus or quite bright and easy to see, such as Algol the Eye of the Gorgon Medusa, but the overall shape can be a little tricky to see. Below the Ecliptic, under Jupiter at the moment, is Cetus the Great Whale, which is practically impossible to see from the city, partly because it is so close to the horizon for us here in Ireland.

These characters are all part of the story of Perseus. Perseus was a demi-god, half-god and half-mortal. In this case, Zeus (in Greek) or Jupiter (in Latin) was the father, while the mother was a mortal woman, Danaë. Danaë was a princess, the daughter of Acrisius, the King of Argos. Acrisius had been told that his daughters son would kill him, so he locked his daughter away. This didn’t stop Zeus, who fell into her bronze prison as rain. In an attempt to avoid the prophecy, the mother and child were cast adrift. They were found by a fisherman, who just so happened to be the brother of the king of another island, Dictys the fisher man was the brother of King Polydectes of Sephiros. King Polydectes fell for Danaë and plotted to get Persues out of the way. He held a feast where every guest was expected to bring a horse. Perseus had no horse and asked if there was anything else he could get. Polydectes sent him to get the head of the Gorgon Medusa.

The Gorgons are very old Greek mythological creatures and their origin and exact features vary from story to story. There were most likely three, with two being immortal, and only Medusa being mortal. According to some stories Medusa had normal hair until Athena turned it to snakes, as a punishment for laying with Poseidon in her (Athena’s) temple. The famous petrifying gaze may have been part of the curse, forcing Medusa to be lonely. With such a powerful adversary, Perseus understandably needed some help. Getting the necessary tools was itself a little quest, with Athena telling Perseus to find the Hesperides, a group of Nymphs, via the Graeae, sisters of the Gorgons.

In the end, Perseus acquired the gear we see him wearing in the constellation. His helmet came from his uncle Hades (Pluto in Latin), the helm of darkness to help him hide, his sword came from his father Zeus, made of magical adamantine, his winged sandals came Hermes (Mercury in Latin), to let him travel quickly. From his aunt Athena (Minerva in Latin) he got a shiny shield, so he didn’t have to make eye contact with Medusa. He also got a bag to put the head in, but we don’t see that in the image used here.

With all of this equipment, Perseus was able to slay Medusa and escape her sisters. We can see the head of Medusa in Perseus hand here, with one of here eyes being marked by Algol. Algol is a pretty bright star and it often appears to vary in brightness over time. This is because it is an eclipsing binary star, really two stars orbiting each other in such a way as that they line up perfectly from our perspective at certain times. It is also known as the Demon Eye or Demon’s Eye, due to this strange winking effect.

This is when Pegasus joins the story, springing fully formed from the neck of Medusa, born of Poseidon (Neptune in Latin) and Medusa. He also had a brother, a golden sword named Chrysaor, but he doesn’t feature prominently in the myths. In the original Greek myths, Pegasus was unique, there weren’t a bunch of other flying horses. This is pretty different from modern interpretations and retellings, where Pegasus is just one Pegasus, one of many Pegasi. Having a flying horse to ride made getting home a lot easier and quicker for Perseus, despite having the magic flying sandals of the messenger god.

On his way home, Perseus passed through Ethiopia, or the kingdom of Aethiopia in Ancient Greek. This is where we meet the other characters, as Cassiopeia and Cepheus were the King and Queen of this kingdom, with Andromeda being their daughter the princess. Queen Cassiopeia had bragged about Andromeda’s beauty, and drawn the wrath of the gods. In Some stories it is to Aphrodite(Venus in Latin) that Cassiopeia compares Andromeda, and saying your daughter is prettier than the goddess of beauty is a bad idea. In others, Cassiopeia claims that Andromeda is more beautiful than the Nereids, who are sea nymphs who often accompany Poseidon, and it is Poseidon who sends floods and a sea monster to Ethiopia out of anger. Cepheus is told by an oracle that only sacrificing Andromeda will save the land, and so Andromeda is chained to a rock by the sea. For this reason Andromeda is often called the Maiden of the Rock or the Maiden in Chains.

The sea monster sent by Poseidon was Cetus the Great Whale. We know a lot more about whales today, but big whales were quite scary in ancient times, a massive whale could sink a ship completely by accident. It would be accident of course, the biggest whales are filter feeders and don’t attack humans or any large prey, but this is a mythical one of course. Cetus the sea monster was luckily turned to stone by Perseus, saving Andromeda.

Of course, they lived happily ever after, but a lot more people had to be turned to stone. In fact, Perseus had already turned King Atlas to stone on his way home. He turned Phineus, who was engaged to Andromeda to stone, in self -defense during their wedding. He turned Polydectes to stone, making Dictys and Danaë king and queen. There are a few stories where Persues turns King Acricius to stone, in others he kills him during a sporting accident, but either way the prophecy is fulfilled.

How did these pictures end up in the sky? According to Greek legends, Pegasus is actually Pegasus, turned into stars after serving Perseus and another hero Bellephoron. Zeus lifted Pegasus into the sky, a process known as catasterism. Athena lifted Andromeda into the sky at the end of her life. The ancient Greek stories often include the legends becoming the pictures in the sky, and these pictures were often used as guides to tell the stories.

Now, you can do the same! Just after sunset in November and December an ancient Greek legend stretches across the sky. Thanks to this post and attached video, you can now retell this legend, just as the ancient Greeks intended. Hopefully you’ll join me back here next time, probably for something less mythological.