StarWatch: Moravian College Astronomy

StarWatch for the greater Lehigh Valley

SEPTEMBER 2003

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366b SEPTEMBER 5-8, 2003: Dieruff Mars Watch: The public is invited to participate in a free Mars watch to be hosted at Dieruff High School in the upper main parking lot along N. Irving Street, Monday evening, September 8, between 9 p.m. and 11 p.m. The cloud or rain date will occur at the same times on the following evening, September 9. Telescopes will be available, especially designed to look at the planets and the moon which will also be close to the Red Planet making for some exciting views. Uranus and Neptune will also be nearby. The public is encouraged to bring along their own telescopes and binoculars so that more individuals can enjoy magnified images. Check www.astronomy.org after 7 p.m. on Monday/Tuesday for a go/no go message on the front page. Directions to Dieruff High School can be found at www.astronomy.org/ASDP-map.html. Telescopes will be set up between 8 p.m. and 9 p.m. If you're bringing equipment, please contact the ASD Planetarium-484-765-5557 and arrive by 8 p.m. to obtain parking near your scope. Everyone should be carrying a flashlight. Dress for colder conditions than expected, making sure your head, hands, and feet remain warm. Layer your garments so that you can add or remove thinner articles of clothing without sweating or getting cold. If the sky is radiantly clear, the temperature could dip into the mid-50s. Telescopically, it will not be difficult to observe the South Polar Cap as a white glimmering speck of light. With careful focusing of the telescope, Martian ground features should become visible in the Southern Hemisphere where it is springtime and winds, generated by daytime heating, are blowing away lighter colored red sand from grayer basaltic rocks. See you at the Mars Watch!

367 SEPTEMBER 10, 2003: The Desire for Power: The public's desire to see Mars through telescopes has been great, but sometimes people think that they are going view the Red Planet as if they have Hubble vision. Mars is a small world, just a little over half the size of Earth. Currently, its disk is 25 seconds of arc in diameter. That is huge for Mars, but small in comparison to the moon which has a diameter 75 times greater as viewed from the Earth. Keep in mind that there are 3,600 seconds of arc per degree and 360 degrees in a circle. Suddenly, Mars becomes extremely tiny compared to the whole sky. Novice observers, taking their queues from telescope manufacturers that hype their scopes' power capabilities, will often try to over magnify a planetary image, thinking that bigger is better. The physics of light limits telescope optics to a maximum gain of 50-power per inch if your telescope is mirrored (reflector), and about 60-power per inch if you own a refractor (lens up top). Magnification can be calculated by dividing the focal length (fl) of the eyepiece, usually given in millimeters and stated on the eyepiece, into the fl of the telescope. The scope's fl is basically the distance from the mirror or lens, where the light is being gathered, to where the eyepiece is located. Measure this length with a ruler, keeping in mind that there are 25.4 mm per inch. Keep units the same in all mathematical operations. Doubling the magnification increases the size of Mars by four, but reduces the image brightness and the entire eyepiece field of view to one quarter of the original values. Air turbulence, Earth's rotation, telescope vibrations, and difficulties in focusing are all increased accordingly. It is no wonder that most people opt to look at Hubble photos rather than peer into their own telescopes.

368a SEPTEMBER 14, 2003: A Great Mars Watch: The Mars Watch, September 9, at Dieruff High School in the upper main parking lot was a rousing success. An assembly of about 250 eager astronomy enthusiasts and StarWatch readers gathered on a crisp summer's evening to witness the burnt orangey hue of the Red Planet including the shrinking South Polar Cap and grayish markings across the Martian landscape. Mars and the full moon made a splendid sight, lighting up a darkened parking lot at Dieruff High School, thanks to the efficient efforts of Steve Budihas, Brian Hassler, and Bob Schafer of Dieruff's custodial crew. Framed by the swaying, fern-like leaves of locust trees, Mars and the moon drew repeated "aaahs" from a crowd that was upbeat and exhilarating, despite the fact that some individuals waited as long as 45 minutes to greet Mars up close at the eyepiece. Children and adults had the opportunity to find Mars and the moon with smaller telescopes located on a blanket in the parking lot. Dieruff's very capable celestial guides included Sarabeth Brockley, Emily Plessl, Evan Burke, Stephen Hopkins, Michael McCormick, Michael Stump, and Jesse D. Leayman. Matt and Marcella Gustintino of Orefield brought along one of two large scopes designed for planetary viewing, setting off a friendly rivalry between observers who took in views using both instruments. Personally, I believe my scope won. Another Mars Watch is planned for the evening of Wednesday, October 15, 7:30-9 p.m. at the top of Dieruff's main parking lot. It's also Dieruff's Open House night, so there will be plenty of other festivities. If it's cloudy, the ASD Planetarium will be ready for walk-in programming, beginning at 7:00 p.m. The topic is Mars, of course! A new StarWatch will appear tomorrow.

368b SEPTEMBER 15, 2003: Lonely Fomalhaut: Situated very low in the south around 11 p.m. and twinkling briskly in the cooler evenings of summer and fall is the lonely star Fomalhaut, the brightest luminary in the constellation of Piscis Austrinus, the Southern Fish. It is not well placed from mid-northern latitudes, but from locations such as Sydney or Buenos Aires, Fomalhaut would appear bright and nearly overhead. From our northern window on the heavens, Fomalhaut, at best, is seen far to our south and only on average about 20 degrees above the horizon. Going north to Maine or even farther north, along the Canadian border, would cause Fomalhaut to sink even lower, to just over a fist in height above a perfect southern horizon. In southern Texas, Fomalhaut can climb to a height of three fists held at arm's length and stacked one on top of the other. The effect of Fomalhaut increasing in altitude as one moves towards the south is a result of our living on a spherical Earth. The changing altitude of the stars was a critical observation made by Columbus, especially with the North Star, as his earlier voyages took him to Iceland where Polaris was high in the sky, and as far south as equatorial Africa where it was seen near the horizon. Columbus was confident that the Earth was a sphere, although he guessed short on its circumference. The reason that Fomalhaut stands so isolated is because we are looking into space at a right angle to the plane of our galaxy, the Milky Way. We see fewer stars and less hydrogen to form new stars. Despite Fomalhaut being the 17th brightest star of the night, its low altitude makes it difficult to see. But don't despair. If you can find brilliant, orangey Mars low in the south around 11 p.m., Fomalhaut will be lower by about a fist and a half. Binoculars will aid you in your search.

369 SEPTEMBER 21, 2003: Mercury in the Morning: There is a story that is told about the great Polish astronomer Nicolas Copernicus, responsible for rediscovering the heliocentric theory that depicted the planets orbiting the sun and not the Earth. The sun was in the center according to Copernicus, although Greek scholars had hypothesized this concept two millennia before Copernicus; but that is another tale. Copernicus was supposed to have lamented as a dying man that he had never seen the planet Mercury. For mid-latitude and for observers at far northern or southern latitudes, seeing Mercury in the sky is a real treat. In my own lifetime I have viewed the second smallest planet of the solar system on only two dozen occasions as compared to 49 times for Halley's Comet in 1985-86. However, throughout this week, but culminating on Thursday through Saturday mornings, the chances for viewing Mercury are dramatically increased. Mercury will be to the west of the sun which means that it will rise before the sun. Its orbital plane will also be tilted steeply to the eastern horizon which will place it much higher in the sky than it is normally found. You'll still need an unobstructed horizon free from trees and buildings and a very clear morning. Binoculars will also prove helpful. Because of Mercury's close proximity to the sun, the planet never gets far enough away from our daystar to be seen in a completely dark sky. At best, Mercury is usually visible about an hour before sunrise or after sunset. Try finding Mercury around 6 a.m. Don't be confused by a very brilliant Jupiter that will also be low in the east. Mercury is below Jupiter. A very thin waning crescent moon will also be approaching Jupiter and Mercury on Monday through Wednesday. See Web StarWatch at the URL below for a map.

370 SEPTEMBER 28, 2003: Astronomy is...: The first task that I accomplish at the start of a new semester is to have my astronomy pupils define the subject that they have elected to study. They create a jot list of all the words they believe to be directly or indirectly related to astronomy. List lengths during the five minutes of writing time have included as many as 65 words. Interestingly, the variety of words that students choose has not really changed that much in the three decades that I have been teaching. Stars, galaxies, quasars, black holes, supernovas, red giants, planets, comets, meteors, and the Big Dipper are all pretty common fare. As our class discussion unfolds, the first part of my original definition evolves quite smoothly. Astronomy is the science that investigates all matter in the universe, but we are really only halfway there. A century ago, when my grandmother, Marie, was looking through the crescent moon of an outhouse on her parent's Haycock Township farm near Quakertown, a young German by the name of Einstein was dreaming about what the universe would look like if he could travel on a beam of light. His conclusions rocked scientific thought and resulted in the special and general theories of relativity, as well as the most famous and popular scientific equation ever devised, E = mc2. E is for energy, m is for mass/matter, and c2 represents the constant known as the velocity of light squared. Light travels at 186,000 miles per second. The equation says a tremendous amount of energy can be reaped from a tiny bit of matter, but it is more profound than that. Einstein said that matter and energy were not only interchangeable, but they are exactly the same thing-E=m. So astronomy includes not only the study of all matter, but also the study of all energy in the universe. Now that's really big.

September Star Map

September Moon Phase Calendar