DECEMBER STAR MAP
MOON PHASE CALENDAR
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DECEMBER 4, 2005: Geminids by Moonlight
One of the sleeper events of the year, the Geminid meteor shower, will be upon us in just about a week. Meteors or shooting stars result from small specks of space debris slamming into the Earth’s upper atmosphere, causing the air to glow. The meteoroids are shed by comets as their orbital paths carry them near to the sun where the sun’s heat vaporizes the comet’s ices and releases the dust trapped within them. The Geminids, however, are uniquely associated with the Apollo asteroid 3200 Phaethon, which like all other Apollo members, has its closest approach to the sun inside of Earth’s orbit. Peak Geminid activity is predicted to occur on Tuesday, December 13 during the three or four hours prior to midnight. Rates from this very consistent shower under dark sky conditions can reach as high as 120 shooting stars per hour, making the Geminids the grandest of all annual meteor events, far eclipsing the more famous August Perseids which usually max at about half of the Geminid rates. Geminid meteors are bright and also enter the Earth’s atmosphere at medium velocities, about 22 miles per second, making them easy targets to spot. That’s the good news. The bad news about the 2005 Geminids can be basically summed up in one simple sentence. The moon will be nearly full and close to the area from which the meteors will be radiating. To see Geminid meteors, I’d go out between nine and 11 p.m. on December 13. Sky conditions will have to be clear. Look N to NE about mid-sky, keeping the moon away from your field of view. Geminid meteors will streak from right to left, but because of the moon, you will only catch the brighter members. Better years lie ahead with 2006 and 2007 offering little moonlight interference.
DECEMBER 11, 2005: Turning the Corner Towards Spring
My project to change the landscape of my backyard continues. My friend Adam Jones and I have moved 220 tons of topsoil and framed what my family has now begun to call the Taj Ma-shed or Shed Mahal. It’s all pretty scary for a guy who probably would be better off living in an apartment. But I like having a small piece of turf which I can call my own, and Coopersburg, where I live, still remains relatively dark. Actually, I’m having a ball except for the copious amounts of rain this fall, mud, snow, mud, bitter cold, more snow, and mud. I keep telling myself that spring is just around the corner. Actually, we did pass a milestone if you’re more of a summer person like I am. The earliest sunset occurred on December 7, about 4:34 p.m. for Allentown. Although it is initially a slow go, in a month sunsets will be happening 20 minutes later. By early February we will have increased our daylight on the sunset side by just under an hour. By early March sunsets take place about 6:00 p.m. Currently, the total amount of sunlight is still decreasing because the later rising sun is outpacing the later setting sun. The big turn of events will happen on the winter solstice, Wednesday, December 21 at 1:36 p.m. EST. The sun, journeying along its path due to Earth’s orbital motion, will have reached its greatest angular distance south of the celestial equator. For my friend, John Shobbrook, in Coonabarabran, New South Wales, Australia, it will be summer. For us, it will be the start of the winter season. However, that is good if you’re building a shed. Each successive day will bring a higher sun, more direct energy, and just a little more daylight. The sum total of these changes will ultimately produce the warmer days of spring, and, of course, more mud.
DECEMBER 18, 2005: Good-bye Venus
Lately, I have gotten a number of phone calls and e-mails regarding that “bright star” hanging low in the southwest after sunset. Perhaps these inquiries have resulted from our focus on Holiday preparations and the “star” that announced the birth of Christ. It is, however, only the planet Venus, but it’s been around in our evening sky since late spring. At that time it was just pulling away from the sun’s glare and in the company of Saturn and Mercury. Venus’ location was to the left or east of the sun, so it had an eastern elongation. This apparition of Venus, however, was not as spectacular as most. Throughout the summer and fall, Venus’ orbital path remained at a low angle to the western and southwestern horizons, even though it was over 47 degrees from the sun at its greatest eastern elongation on November 3. Put simply, by the time it got dark, Venus was too close to the horizon to be easily seen. Through a telescope at greatest eastern elongation, Venus would have appeared like a quarter moon, half in light and half in its own shadow. Since then, Venus has been rapidly approaching the Earth headed for inferior conjunction on January 13, when it will be positioned between the Earth and the sun. Still prominent in the twilight sky, Venus will set about 1-1/2 hours after the sun on New Year’s Day and a scant 35 minutes after sundown on January 5. Through a telescope, watch as Venus’ crescent rapidly shrinks during the next several weeks as the planet’s apparent size becomes larger. On January 5 Venus will be only six percent sunlit, and it will appear as a very thin crescent. By late January, Venus will have traveled well west of the sun, and it will be rising more than an hour before our daystar, an easy target in the brightening eastern dawn sky.
DECEMBER 25, 2005: She Was the Sun; I Was the Moon
It was a blustery Tuesday, October 3, 1978. I answered the jangling phone on the eighth or ninth ring, and it was the voice of my friend Charles J. Takacs, director of the East Penn Planetarium. Charlie had a big problem. He had to speak that evening about the moon and his kids had suddenly become ill. His wife had to work. He had desperately searched for a babysitter, but none were to be found. I would have normally said no, but for some strange reason, I had just finished preparing a unit on the same topic which I would start teaching the following week. Several hours later, I found myself entering the lecture room of the Lehigh Valley Amateur Astronomical Society. And there she was, like a gentle spring day, sitting quietly in the center of a room filled with activity. I sat behind her. My heart raced. No ring, I spied. Then another guy sat next to her. “Bad move,” I thought. “I should have done that—started a conversation,” but it was now time for my presentation, and I had other concerns. I remember that my talk was well-received, with lots of audience response. She asked a question! Were there caves on the moon? “Surely not limestone,” I retorted. “The moon has no water, but fault caves and lava tubes had to be in abundance.” So the answer was yes. Afterwards there were many more questions, and she hung always just beyond reach. Finally, I said, “Next week.” “I’ll come back and we’ll talk.” So I left, but she followed me into the chilled night air, and there we spoke for nearly two hours. Her name was Susan. We had briefly met 10 years earlier. I had forgotten, but she had journaled it. She became my sun; I was the moon. She found the words; I was the tune. It was a wonderful Christmas. We married in June of 1982. Joyous Holidays!
Peace on Earth:
A four day waxing crescent moon adds an ambiance of Christmas to the steeple of Trinity Episcopal Church in Bethlehem. Digital photography by Gary A. Becker...