Skywatch for the week of February 17, 2020
Tue Feb 18, 2020 ANCIENT ORION In the southern sky after sunset the ancient hero Orion the Hunter dominates the winter night. One of the oldest of the established constellations, Orion is perhaps also the most readily recognizable – the three bright stars close together in a line – the hunter’s belt - make it easy to find. The venerable origins of Orion can be traced back to the Mediterranean and the Middle East: In Chaldea he was Tammuz; to the Syrians, the giant Al Jabbar. The ancient Egyptians knew him as one of their most revered gods, Osiris, and it’s been claimed that the Great Pyramid of Khufu, along with two others, were built to mirror the three belt stars – Alnitak, Alnilam and Mintaka. But the Greek myths are the ones we recall the best. He was a giant, the son of Poseidon, who often hunted with the moon goddess Artemis, but was stung by Scorpius for boasting too much of his strength, then finally restored to life in the heavens where we see him tonight.
Wed Feb 19, 2020 NICOLAUS COPERNICUS The astronomer Nicolaus Copernicus was born in Poland on February 19th, 1473. He advocated the heliocentric theory, which placed the sun in the center of the solar system, with the earth and other planets revolving about it. Copernicus received praise and encouragement from the Bishop of Kulm and the Archbishop of Capua and some scholars, but his ideas were also ridiculed by others including Martin Luther, who once said, “This fool wants to turn the whole art of astronomy upside down!”. Until the middle of the 17th century, the teachings of ancient Greek philosophers like Aristotle were considered the final word on matters scientific, and Copernicus’ new system wasn’t any more accurate than the old geocentric, or earth-centered model. But the heliocentric or Copernican model eventually simplified and explained the motions of the planets better than the geocentric system.
Thurs Feb 20, 2020 THE DISCOVERY OF PLANET X On February 18, 1930, Planet X was discovered by Clyde Tombaugh when he worked at the Lowell Observatory in Flagstaff, Arizona. He didn't have a University degree, but at the time was a talented amateur astronomer. Tombaugh’s number one job was to make and search photographic plates of the sky, looking for anything that might shift its position from one night to the next, as seen when comparing one photo to another picture of the same part of the sky taken a few nights later. It was painstaking work, but rewarding; Planet X was discovered out in the direction of the constellation Gemini, which is well up in the eastern sky after sunset tonight. But Planet X isn’t there anymore. This distant world is now six constellations over to the east, in Sagittarius. Oh, and it’s not called Planet X anymore; shortly after its discovery it was renamed Pluto.
Fri Feb 21, 2020 AURIGA THE CHARIOTEER High in the northern sky this evening there is a somewhat obscure constellation called Auriga, the Charioteer, in legend and myth, an early king of Athens, the son of the blacksmith god Hephaestus or Vulcan, and the inventor of the chariot. Another story portrays him as Phaeton, whose father was the sun god Helios, and who drove the solar chariot on a reckless path across the sky. Now if you're good at imagining constellation shapes, you'll immediately see Auriga in all his glory - a man, driving a chariot, while holding on to a whip in one hand, and a bunch of small goats in the other. But if you have that kind of imagination, then I probably didn't have to tell you all that. For the rest of us, Auriga looks like a pentagon shape - a five-sided figure of stars, marked by a bright yellow star - Capella, the head of the charioteer. Look for the goat kids also, a few tiny bright stars just to the south of Capella.