OCTOBER  2003

OCTOBER STAR MAP | STARWATCH INDEX | MOON PHASE CALENDAR

Print Large Sky Charts For 10 p.m. EDT:   NORTH | EAST | SOUTH | WEST | ZENITH

371    OCTOBER 5, 2003:   Columbus's Winds of Fortune

When Columbus put to sea from Palos, Spain on August 2, 1492, he had a simple but eloquent plan. It was to first sail SW to the Canary Islands, resupply, then head due west until he encountered Japan, estimated to be 2,500 miles distant. Homeward bound, Columbus would depart towards the NE, then sail eastward until he reached the Iberian coast and eventually find Palos. Earlier in his life, Columbus had sailed north past the frigid waters of Iceland and south along the Gold Coast of Africa. From these experiences, he realized that there were prevailing wind patterns at certain latitudes that could carry him either westward or eastward. The Canary Islands were in the easterly trade winds, a climatic pattern that results from a band of descending air girding the Earth about 30 degrees north and south of the equator. As the air moves down, it compresses, warms, and dries, creating the world's great deserts, such as the Sahara. The air then diverges either northbound or southbound. The southward moving air begins with a speed equivalent to the rotational velocity of the Earth at that latitude, about 900 miles per hour. As the air wanders south, the ground over which the air is traveling moves ever faster. The air currents lag behind the increasing speed of the ground. Since the Earth spins from west to east, the slower moving air must be deflected towards the west, causing wind patterns to originate from the east. Northbound air begins with the same 900 mile per hour velocity and surges ahead of the slower moving ground over which it passes, causing weather patterns to move from west to east. Columbus had two 1000-mile wide superhighways of moving air to take him wherever he wanted to go and the courage to trust their constancy across uncharted seas.

372    OCTOBER 12, 2003:   Hawk Mountain Eclipse

My wife Susan just said, "Not another lunar eclipse, Gary. Every time I turn around there is another one." And she's right, well, at least lately. Set aside the early evening hours of Saturday, November 8th, starting at 6:30 p.m. to witness what I call a primetime celestial event. This eclipse, just like last May's lunar eclipse will be total, meaning that the bright full moon will be gradually muted as it moves completely into the shadow of the Earth from 6:32 p.m. to 8:06 p.m. EST. From rural locations, the country sky made bluish and bright by the full moon's reflected sunlight, will gradually fade and darken, revealing the gossamer texture of our Milky Way galaxy arched high overhead. A star-splashed backdrop of hundreds of luminaries will also be unveiled as the moonlight fades. At the onset of totality at 8:06 p.m. EST, a grayish red or brownish red moon positioned low in the southeast will add additional luster to an already spectacular firmament which will also include the red planet Mars, fading, but still beaming brightly in the south. During totality, which ends at 8:31 p.m., it will be possible to view summer and fall constellations, and such celestial gems as the Great Galaxy in Andromeda, the Double Cluster in Perseus, and the Ring Nebula in Lyra. Throughout totality, the darkness of the sky will rival any moonless night but still include the dim, colorful, soft glow of the eclipsed moon in the SE. Hawk Mountain Sanctuary has invited my StarWatch team of enthusiastic students and dedicated volunteers supporting the ASD Planetarium to showcase telescopically the November 8th event at the Sanctuary. More information about this free public skywatching event starting at 5:00 p.m. will be discussed in next week's column.

Mars Watch Program to be held at
Dieruff High School, October 15th

The Second ASD Planetarium Mars Watch is scheduled for Wednesday, October 15, 7:30-9:00 p.m. in the upper main parking lot along North Irving Street at Dieruff High School. Planetarium programs, starting at 7:00 p.m. will also be given concurrent with the Mars Watch. Junior, Evan Burke, an astronomy student at Dieruff, stands ready to help those wishing to look at Mars. Photo by Steven Walker of "The Chronicle." The Mars image in the background was photographed by Glen Hacker of Reading several days after the first Mars Watch, Sept. 9 and gives an excellent rendition of what was seen through telescopes at Dieruff on Sept. 9. Note the South Polar Cap at the three o'clock position.

373a  OCTOBER 19-21, 2003:   See the Lunar Eclipse at Hawk Mountain

Hawk Mountain Sanctuary has invited my StarWatch team of ASD Planetarium students and adult volunteers to set up their telescopes to observe the total lunar eclipse at the Sanctuary on Saturday evening, November 8. This event is free to the public. I will be speaking about lunar eclipses at 5:30 p.m. in the Visitor Center. Participants are encouraged to bring along a snack or picnic supper, and a hot beverage, as well as their binoculars, spotting scopes, and telescopes. Hawk Mountain is encouraging partakers to arrive early and enjoy the trials before coming indoors for the presentation. Afterwards, it will be off to the telescopes to watch the eclipse unfold. The moon enters the Earth's shadow at 6:32 p.m., but about 15 minutes before first contact, the leading limb of the moon will begin to appear dusky as it approaches Earth's main shadow, the umbra. It will take the moon one hour, 34 minutes to be completely eclipsed. During this time small and large telescopes will reveal the Earth's shadow sweeping past craters, minute by minute, gobbling up more and more of the lunar landscape. Totality lasts a scant 25 minutes from 8:06 to 8:31 p.m. Luna will then emerge from Earth's shadow in reverse fashion until the landscape is bathed once again in brilliant moonlight. The eclipse is over at 10:05 p.m. Sue Wolfe, Director of Volunteers at Hawk Mountain Sanctuary, cautions that weather conditions in early November can be cold and windy. Head, hands, and feet must be well protected. Everyone should have a flashlight and an extra set of batteries. Lawn chairs, blankets, and more clothing than you think you'll need will maximize your enjoyment of this primetime eclipse. A new StarWatch will appear mid-week followed by more Hawk Mountain information next Sunday.

373b  OCTOBER 22-25, 2003:   Total Lunar Eclipses Not So Common

The primetime, total lunar eclipse that will be taking place across Lehigh Valley skies early on the evening of Saturday, November 8, starts at 6:32 p.m. and continues until 10:05 p.m. EST. Mid-totality, when the moon has penetrated the Earth's shadow to its deepest point, happens at 8:19 p.m. EST. The last total lunar eclipse visible in the US occurred on May 15, and the next one after November's event happens on October 27, 2004. On the other hand, the last central solar eclipse, where the moon's umbra swept across any part of the continental US, happened on May 10, 1994. The next US central solar eclipse takes place on May 20, 2012. From these facts it seems that central solar eclipses, when the center of the moon passes across the center of the sun, and which include annular (ringed) and total solar eclipses are more rare than total lunar eclipses. Just the opposite is true. Think of it this way. For a central solar eclipse to happen, the moon's primary shadow called the umbra must point towards the Earth, a target area about 8,000 miles in diameter. But for the moon to be totally eclipsed by Earth's shadow, it must pass through a target zone about 5,700 miles in diameter. That is the size of the Earth's shadow at the moon's average distance. It doesn't take a rocket scientist to realize that it is more difficult to hit a 5,700-mile bull's eye than it is to hit an 8,000-mile bull's eye. A total lunar eclipse must be a rarer event than a central solar eclipse. Here is the catch. To see a total solar or annular eclipse, you almost always have to travel to the location of the moon's shadow, making these events seem less common. When a total lunar eclipse happens, more than half of the world is sitting in the grandstand seats and is able to see the event if the weather cooperates, making total lunar eclipses seem more common.

374a  OCTOBER 26-28, 2003:   Dress Warmly for the Hawk Mountain Eclipse

During this past week the reality of fall has rapidly begun to settle in. Crisp, chilly mornings, the ritual of scraping frost-covered windows, and the vibrant splash of winter stars in the south when I pop outside after grabbing the morning paper, have all begun to chisel their stark reminders into my summer-skewed brain. Now that the clocks have fallen back and the cloak of night nuzzles in an hour earlier, I must accept the inevitable. Thanksgiving, Christmas, and snow days are just around the next bend in the pathway of my life. All of these signs remind me to tell you that if you're planning to make the drive to Hawk Mountain Sanctuary to view the total lunar eclipse on Saturday, November 8th, please dress warmly. Your head, hands, and feet are the critical body areas that must be protected and kept comfortable for two to three hours. I would suggest thermal underwear as a start, then layer your clothing, rather than wearing one thick garment. Wind resistant materials, such as Gortex, will definitely prove useful as an outer shell. Hawk Mountain can be a blustery place, and the trees, although now in their full spray fall of colors, will be bare-branched by the 8th of November. The forest will provide little to no protection from the wind. Bring a warm drink along, and don't forget a small flashlight with an extra set of batteries. The evening begins in the Visitor Center at 5:30 p.m. with a short talk about eclipses. The lunar eclipse begins promptly at 6:32 p.m. My students and friends will be providing about a dozen telescopes for your viewing pleasure, but if you own binoculars or a spotting scope, please bring them along. This is ideal equipment for eclipse viewing. Directions to Hawk Mountain will be given next week. A new StarWatch will appear on Wednesday.

Hawk Mountain Sanctuary will provide a magnificent backdrop for viewing what will hopefully be a colorful total lunar eclipse on Saturday, November 8. By this time, however, the trees will have lost their leaves and conditions could be cold and blustery. Please read the article above. Directions to Hawk Mountain from the Lehigh Valley are provided below. Aerial photography by Adam R. Jones...

From Allentown take I-78 west to Exit 35 at Lenhartsville, PA. At the bottom of the exit, turn left onto Rt. 143.

At the bottom of Exit 35, turn left (north) onto Rt. 143 and proceed for three miles to the Sunoco gas station.

Turn left at the Sunoco gas station and continue seven miles through the small towns of Albany and Eckville to Hawk Mountain Sanctuary.

Watch the moonrise from South Lookout about 4:45 p.m., then walk down to the Visitor Center for a presentation about eclipses at 5:30 p.m. The total lunar eclipse begins at 6:32 p.m. All photography by Gary A. Becker...

374b  OCTOBER 29-NOVEMBER 1, 2003:   Predicting a Colorful Eclipse

The total lunar eclipse that will be visible from all of the continental United States on Saturday, November 8, favors areas east of the Mississippi and particularly the East Coast. The moon enters the Earth's shadow, called the umbra, at 6:32 p.m. EST. Totality begins at 8:06 p.m. and lasts only 25 minutes. The moon completely exits the umbra by 10:05 p.m. EST. The maximum duration for totality in a central lunar eclipse is one hour, 47 minutes. During the November 8 eclipse, the moon will always be close to the Earth's shadow boundary. This should create a particularly colorful eclipse, especially if viewed through small telescopes, spotting scopes, or binoculars. I would expect to see various shades of deep browns, gray reds, and perhaps even orangey yellow hues under low magnifications. That's exactly what I predicted for last May's total lunar eclipse, which also stayed near the edge of Earth's shadow during totality, and that is exactly what did NOT happen. Most veteran observers described the moon during totality as dark and not overly colorful. Eastern Pennsylvania was cloudy on May 16th, so there was no need to slap myself in public, but now it's time to confess. So why do I feel the need to go out on a limb again? Because it's fun to make a prediction based upon the facts. Isn't that what science is all about? Some of the sunlight that is passing through Earth's atmosphere near the shadow's edge will be bent into the umbra. Shorter wavelengths, like blue light, are scattered and attenuated by the air. Only the longer wavelengths of yellows, oranges, and reds can penetrate into the shadow to color the moon's surface. This effect is most pronounced near the shadow boundary, exactly where the moon will be throughout totality. Get ready for a colorful eclipse.