Before dawn on Saturday – January 17, 2015 – watch for the waning crescent moon near the planet Saturn and star Antares, brightest star in the constellation Scorpius the Scorpion. Not a morning person? Then look for the constellation Orion the Hunter, which dominates the sky in early evening. In the lore of the sky, Orion is tied intimately to Scorpius, which – at this time of year – can be found rising shortly before dawn.
Orion and Scorpius are both easy to pick out. Saturday morning, especially, you’ll have no trouble locating Scorpius since the moon will be close to its brightest star, Antares.
And Orion in the evening sky? If you pick out any pattern among the stars on January evenings, that pattern is likely to be Orion. Just go outside and look for a short, straight row of three medium-bright stars. These stars represent Orion’s Belt.
By the end of January or in early February, as darkness ebbs into dawn, you might even catch the two stars marking the Scorpion’s stinger coming up south of the sunrise point. These stars – Shaula and Lesath – rise about four minutes earlier each day. Even if you miss them tomorrow, you should be able to view the entire Scorpion just before dawn in a week or two.
So Orion is up in the evening now, and Scorpius is up before dawn. Next summer, when Orion is up before dawn, Scorpius will be out in the evening. Orion and Scorpius never appear in the sky at the same time.
Legend has it that Orion the Hunter was very vain. He boasted that no animal on Earth could kill him. But the Scorpion did sting Orion, and the Hunter died of its poison. Now, according to this ancient myth, the bitter hatred between these two constellations is so great that they can never been seen in the sky simultaneously.
We today have a different interpretation of the fact that Orion and Scorpion are never in the sky together. Scorpius is located in the direction toward the center of our Milky Way galaxy. Orion is located in the opposite direction. They’re never in the sky at once simply because they’re located in opposite directions in space, as seen from Earth.
Bottom line: Why Orion the Hunter and Scorpius the Scorpion don’t appear in the sky at the same time. Plus … the predawn moon on Saturday, January 17, 2015 near Antares, Scorpius’ brightest star.