Skywatch for the week of February 15, 2021
Mon Feb 15, 2021 GALILEO’S BIRTHDAY
The astronomer and physicist Galileo Galilei was born on February 15 in the year 1564. Galileo did not invent the telescope, but when he heard of its invention, he built his own, and like other astronomers of the 17th century, Galileo aimed his telescope at the sky and made some amazing discoveries. He saw the rough features of the moon, its mountains and craters, which suggested that it was another world in space, like the earth. He discovered the four largest moons of Jupiter, named the Galilean satellites in his honor. Using safe projection methods, he observed the sun and saw dark spots on its face – sunspots. He noted that the planet Venus went through phases like the moon, which showed that it orbited the sun and not the earth. And he saw the myriad stars of the Milky Way - more stars than could be seen by the unaided eye alone. There evidently was much more to the heavens than had heretofore been realized.
Tues Feb 16, 2021 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 17, 2021 PLACES IN THE SKY FOR FEBRUARY
Of the eighty-eight official constellations, can you identify the thirty-ninth largest one? It is bordered on the north by Triangulum and Perseus, on the south by Pisces the Fish, Cetus the Whale and Taurus the Bull, on the west by Pisces again, and on the east by Taurus again. Three middling-bright stars – Hamal, Sheratan and Mesarthim, form its head; however the rest of this constellation is in one of the darkest regions of the night sky, and there are no familiar nebulas or star clusters within its borders. But many of its stars are known to have planets. In mythology this animal represents the golden fleece, sought by Jason and his Argonauts in the land of Colchis, where it was guarded by Draco the Dragon. Tonight the waxing crescent moon hangs below the stars of this elusive constellation. Can you name this star figure, the first constellation of the Zodiac? The answer is Aries the Ram, in the southwestern sky after sunset., 2020
Thu Feb 18 2021 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 19, 2021 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.