StarWatch for the greater Lehigh Valley



Print Large Sky Charts For 9 p.m. EST:   NORTH | EAST | SOUTH | WEST | ZENITH

[Moon Phases]


433    DECEMBER 5, 2004:   Bundle Up for the Geminids
I have hiked Mt. Washington in New Hampshire under some very inhospitable conditions. In one winter climb, with Adam Jones of Allentown, the summit conditions were 0 deg. F. with 80 mph sustained winds. That translates into a wind chill of approximately –60 deg. F. So was I bone-numbingly cold? The answer was no. I was exerting myself in the buffeting air, and surrounding my four layers of thermals was a Gortex outer shell that stopped the wind “cold.” Inside my little spacesuit the weather was just fine. This will not be the case for the Geminid meteor shower set to peak in the late evening hours of December 13. If it is clear, it will be cold, and no amount of layering will prevent your inactive body from surrendering to the elements. However, you can help yourself survive longer by making sure that your head, hands, and feet are adequately protected from heat loss. Layer up and then additionally wrap yourself in a warm sleeping bag for extra protection. You may just last long enough to begin appreciating nature’s finest annual display of meteors, radiating in the east from above the bright star Castor in the constellation of Gemini. A map can be found with this edition of web StarWatch. Even though 10:20 p.m. is the projected peak activity, North America will not have rotated into its prime position. Expect rates of 25 meteors per hour from suburbia, and less from the city. Rates should increase after midnight. It is similar to the greater amounts of rain that pound the front windshield of a moving vehicle versus the rear window. After midnight we will spin into the direction of Earth’s orbital motion and gather up many more meteoroids, pumping rates up to perhaps one meteor a minute.

[Geminid Meteor Shower]

434    DECEMBER 12, 2004:   Low Sun
We have entered into the season of the long shadows. Winter solstice will be upon us on December 21 at 7:40 a.m. EST, the shortest day of the year. With a horizon-hugging sun that rises in the southeast and sets in the southwest after only nine hours, it is no wonder that temperatures have been decreasing with thoughts about Caribbean, Mexican, and Hawaiian vacations increasing. So why is the sun higher in these locales, and where would the sun be found directly overhead? Let us make it noon on the first day of winter in Allentown, about 40 degrees north of the equator. The sun is at its highest point for the day, but still only 26-1/2 degrees above the horizon. We also need to freeze time in this mental exercise. If I started walking due south in the direction of the sun across the spherical Earth, the sun would climb ever higher and higher into the sky. On my journey, I would pass just west of Cape May, NJ, out into the western Atlantic, across the eastern Bahamas, Cuba, and the Caribbean Sea, through Columbia, past the equator, and to the southern coastline of Peru. Still the sun would not be directly overhead. I would have to travel an additional 550 miles south into the eastern Pacific before my goal would be achieved. My location would be on the Tropic of Capricorn, 23-1/2 degrees south of the equator and 300 miles west of Punta Tetas, Chile. It is no wonder for us in the Northern Hemisphere, at a mid-latitude site, that the sun must rise south of east, set south of west, and that the sun must be low in the southern sky at noon during winter. All of these seasonal shenanigans of high sun and low sun are simply a reflection of Earth’s axial tilt. The big perk of winter solstice is that everyday thereafter, the noonday sun climbs just a little bit higher into the sky.

435    DECEMBER 19, 2004:   Listen to the Music
Coming home from church several weeks ago, I remarked to myself about the beauty of the Middle Eastern music to which I was listening. I did a double take when on the next track, I was suddenly confronted with a vocal in Hebrew. The CD was titled Ancient Echoes: Music from the time of Jesus and Jerusalem’s Second Temple. Of course, I knew where ancient Judea was, but it never occurred to me that cultures which have seen so much turmoil would have such commonality with respect to music. I thought it was a fairly inane misconception coming from an educator that instructs students in the most diverse school system in the region, Allentown. For a moment I felt embarrassed, but since this was all a mental exercise blasting through my brain in the blink of a second, it went unnoticed, even by my wife. It is, however, no misconception that those same cultures which are representative of the student population of Allentown all enjoy coming to my planetarium. The District’s first graders, currently partaking in the “Stars from Santa’s North Pole,” collectively go nuts when the sun sets, and the stars begin to appear against a darkening sky. Of course, if you believe in the fantasy of Santa, the world is a simpler place. But I have often wondered if there isn’t something in our collective ancestral memories that unites all humankind with the beauty and the mystery of the heavens. We all see the same sun, moon, planets, and stars, and for most of us, the same star patterns tease our imaginations. Watch the moon wax towards its full phase this week and know that everyone worldwide is observing the same phenomenon. Perhaps we need stop beating each other up and listen to the collective music of the spheres, not just in this Season of Light, but for all future times. Happy Holidays!

436    DECEMBER 26, 2004:   Fixated on Saturn
Saturn is now coming into prime focus and would make an excellent first target if a telescope was under your Christmas tree. By 9 p.m., the Ringed World is already high enough in the east to be accessed from most observing locations. Look for it below and to the right of the two brightest stars of the Gemini Twins, Castor and Pollux. Each star is easily visible from urban locations, but Saturn will outshine them all. Give your telescope at least an hour to cool down from the warmer conditions of your house, and bring along a chair for extra comfort. Dress warmly protecting head, hands, and feet. The more stress-free you feel, the more you will see. Since 1995, Saturn has been tilted back so that we have been viewing its southern hemisphere. The rings have been open and easily accessible through even the smallest telescopes since 1999. But this will be changing after 2005 as our observing angle places us more and more in line with the plane of Saturn’s rings. By 2009 the rings will disappear for a short time giving Saturn its most undistinguished look. Don’t forget to examine the waning gibbous moon as it slices through the scene during the earlier part of the week. On December 27 the moon is only two degrees to the right of Pollux and five degrees from Saturn, a splendid sight through binoculars. Telescopically, view the moon’s surface features near the terminator, the region where, in this case, the sun is setting. Here the shadows are longest, and low-relief detail is more easily perceived. January 2-3, the moon approaches Jupiter, and then passes Jove by January 4. This scene should be best viewed at 6 a.m. when Jupiter is due south and about halfway up in the sky. Catch Venus, Mercury, and Mars this week, just above the eastern horizon at 6:30 a.m.

December Star Map

December Moon Phase Calendar