Venus has recently slipped from the morning sky, and is now closing on the Sun. She is not to be seen again until her return to the western sky at the end of May in her 'Evening Star' apparition. Skywatchers can still find traces of romance above though Venus has temporarily left the stage — Perseus and Andromeda, the Hero and the Princess, are prominent this time of year from nightfall until about midnight.
This is the view west, early evening, on Valentines Day. Pegasus shows at the horizon just west of the crescent moon with Andromeda and Perseus lighting above.
The Greek myth of Perseus and Andromeda is a convoluted one, starting with a king being told that he will one day be killed by his grandson. To curtail this possibility, the king locks his daughter up in a tower. This is not an impediment to lecherous Zeus who makes an illicit visit to the maiden in a shower of gold. Confronted with the unpleasant fact of his grandson and unwilling to kill the son of Zeus, the king sets the mother and child adrift at sea. Unfortunately, the refuge they eventually find doesn't keep them safe for long, as Perseus's mother faces unwelcome advances from another suitor, the resident king. To get Perseus out of his way, the king tricks him into promising that he will bring back the head of Medusa, one of the Gorgon sisters whose gaze turns living beings into stone.
Lucky for Perseus, the Olympian gods are on his side. With Athena's reflective shield, Hermes' winged sandals, Zeus's sword, and Hades' gift of darkness, the hero achieves his task. On his way back to present Medusa's head to the king, Perseus spies a maiden chained to a sea wall. Her mother, Queen Cassiopeia, has been heard bragging that her daughter, Andromeda, is more beautiful than the Nereids, nymphs of the sea. To punish her hubris, Poseidon has sent a sea monster to terrorize the country. An oracle tells Cassiopeia's husband, King Cepheus, that only the sacrifice of Andromeda will assuage this insult.
Perseus cuts Andromeda's chains and slays the monster. When another suitor arrives to claim Andromeda, Perseus uses Medusa's head to immobilize him and his soldiers. The same fate awaits his mother's predatory royal suitor. Eventually, the head of Medusa is given to Athena who displays it on her shield.
Several actors in this ancient drama star in the winter sky. Perseus and Andromeda appear near the zodiacal constellations of Taurus and Aries. Locate Jupiter currently traveling in Taurus and move your eye further up into the night sky – away from Orion – to find Mirfak, which marks Perseus's head. In his left hand, he holds Medusa's severed head, symbolized by Algol, the demon star. Andromeda appears to Perseus's west. By 11 p.m., her alpha star, Alpheratz, will just be setting.
Then there are the circumpolar constellations of Cassiopeia and Cepheus. Cassiopeia is especially easy to recognize because the figure resembles a "W" or an "M." To humiliate her, Poseiden had her placed in the heavens in a market basket so that there would be times when she appears upside down. Her husband Cepheus is just above her, in the shape of a peaked house, very close to Polaris, the North Star. The sea monster, Cetus, can be found just below the ecliptic and the faint constellation Pisces. And flying west before Andromeda, both of them sharing the star Alpheratz, is Pegasus, the divine winged horse foaled when Perseus decapitated Medusa.
And what about that grandfather, so worried about the prophecy that he exiled his own daughter and grandson? Although he never met Perseus, the two attended the same athletic ceremony, and when Perseus threw a discus, a chance wind sent by the gods carried the discus far from its path, striking the king and killing him. No eternal glory for him in the starry night, but the story he set into motion is there to trigger thoughts of stirring heroic deeds and deathless love.
Perseus, from the Cosmography of the Sala del Mappamondo, Villa Farnese, Caprarola, Italy. The artist is unknown. 1575. Sword of Zeus, Winged sandals of Hermes, the Hero holds the severed head of Medusa. (Try not to look.)