Mon Dec 16, 2024 DECEMBER FULL MOON/GEMINID METEORS
Today the moon, just past full, rises out of the east at sunset. December’s full moon is known as the Big Winter Moon – that’s according to the Creek and the Seminole Indians. To the Algonquin Indians and to colonial settlers, this is the Long Night Moon, another reference to the beginning of winter, when days are short and nights are long. The Sioux call this the Moon of Popping Trees, perhaps because the cold air freezes water, causing the trees to crack and pop. The Winnebago name it the Big Bear’s Moon, and the Cheyenne say it is the Moon When the Wolves Run Together - pack hunters searching for food before the snows of winter. There’s also a meteor shower called the Geminids going on right now. But with that bright full moon up there, this year’s display will be very hard to see.
Tue Dec 17, 2024 TYCHO BRAHE
Tycho Brahe, born on December 14th, 1546, was a Danish nobleman who had an artificial nose made of brass – he’d lost his original nose in a fencing duel over an argument with another scholar about a math problem. (Actually, this happens a lot. Not the duel, the arguing.) But it turns out he was a great astronomer. Tycho proved by its parallax that a comet was far beyond the moon; it used to be thought that comets were simply gases in the atmosphere. From Tycho’s island observatory, and before telescopes were invented, he made incredibly accurate measurements of star and planet positions. It was this data that made it possible for his colleague Johannes Kepler to figure out that the shapes of the orbits of planets about the sun are not round, but elliptical.
Wed Dec 18, 2024 MOON AND MARS TOGETHER
Tonight you’ll find the waning gibbous moon over in the eastern sky a couple of hours after sunset. Nearby it this evening there is a very bright, solid-looking star that has a slight red color or tint. This is the planet Mars. Although the two of them look like they are right next to each other, they are really millions of miles apart! The moon is much closer to us, just a quarter of a million miles out, which is why, even though it’s smaller than Mars, we can make out many of its features with telescopes, binoculars and even the unaided eye! Maria, craters and mountains stand out in great detail. But if you aim a telescope at Mars, you’ll just see it as a small orange disc, with maybe a hint of one of its polar ice caps.
Thu Dec 19, 2024 WINTER’S BEGINNING AT NEWGRANGE
There’s a place in Ireland called Newgrange, but there isn’t anything new about it – in fact, it’s literally as old as the hills, being a hill itself. Five thousand years ago, the Irish built a giant earth mound, over an acre across, and surrounding it they set up great stones. Ancient tomb, ancient temple, Newgrange probably served both these functions. And like Stonehenge in England, Newgrange is astronomically aligned. For a few days before and after the winter solstice - the beginning of winter - sunlight travels through a roof box or window over the main doorway. The shaft of sunlight travels all the way down a long, narrow corridor, until it lights up a small chamber at the center of the mound. It happened long ago, and it happens now.
Fri Dec 20, 2024 WINTER SOLSTICE/URSID METEORS
Winter begins in the earth’s northern hemisphere a little before sunrise tomorrow December 21st, at 4:20 am, Eastern Standard Time. It's at this exact moment that the sun's rays fall most directly on the Tropic of Capricorn, twenty-three and a half degrees below the equator, where summer is beginning. For us in the northern hemisphere, today marks the shortest period of daylight, and also the longest night of the year. As our winter season begins, we will be treated to a meteor shower called the Ursids. Best views will be from midnight until dawn, but there will be some visible in the late evening too. Grab a reclining lounge chair, dress warmly, get away from bright streetlights and face east, and hope for clear, dark skies.