StarWatch: Moravian College Astronomy

StarWatch for the greater Lehigh Valley

SEPTEMBER 2001

SEPTEMBER STAR MAP | INDEX | MOON PHASES

262 SEPTEMBER 2, 2001: Moon Hides Saturn: The moon revolves around the Earth; the Earth and planets revolve around the sun. And so the heavenly dance continues now and for always with interesting twists and turns as the partners group, move on, and group again. The steps are never quite the same, but the beauty of seeing moon and planets in a sparkling clear twilight sky keeps many of us continually looking skyward. There is good reason to continue the vigilance for next week the moon returns to the morning sky teasing Jupiter and Venus but hiding Saturn. Here is how the event will unfold for Saturn. The moon starts the week in its full phase, visible to us all night. But as the week progresses, it slips into the morning sky as it wanes, rising later each evening. By next Sunday, September 9th, the moon is nearly at last quarter rising just after 11 p.m. Fourteen minutes later, Saturn rises just to the moon's east. As the night progresses into the 10th, the moon creeps ever closer to Saturn. By 5:30 a.m., about an hour before sunrise, the moon is just over one and one-half degrees from Saturn. Now it's time to begin following the pageant with binoculars and telescopes, because as the hours unfold it will become obvious that the moon is going to occult (hide) the Ringed World. For Allentown, it happens at 9:19 a.m. in a sun-drenched sky, but if it is clear enough, observers using telescopes will be able to witness this daytime occultation. Keep in mind that the moon is much brighter than a blue sky, so this event will be visible through telescopes. Hawaiians see the occultation at night just after 1 a.m. HST, while observers along the coast of California see it just before 5 a.m. Follow the planetary action by downloading a map at this week's web version of StarWatch.

263 SEPTEMBER 9, 2001: Digital Astrophotography: The digital camera revolution has been here for several years, but few of us have taken the opportunity to point their digital cameras to the heavens and record the sky. Since the early 1990's, amateur astronomers have had a variety of sophisticated techniques to image electronically sky events. These usually required expensive and highly specialized cameras equipped with very sensitive and cooled CCD chips. But what about the regular point and shoot digital cameras that anyone can purchase at a photo store? The astronomical subjects that my two and three year old Kodak 290 and 260 cameras have captured have elated me. I have concentrated on events that can be observed after sundown or before sunrise involving the moon, planets, and bright stars. I have also had some success photographing scenes under the light of a full moon. Don't however, expect your digital camera to reveal the intricacies of the Milky Way, or for that matter, star patterns. Since digital "film" is free, the key is to experiment, take lots of pictures, and delete the bad ones. This week, Venus, Jupiter, Saturn, and the moon are cooperating spectacularly in the morning. Start shooting about 5:15 a.m., 90 minutes before sunrise. Attach your camera to a tripod and start with your longest time exposure. About half of the cameras sold today can take time exposures between 4 and 30 seconds. As the light in the east brightens, adjustments in exposure length will have to be made. You will discover a combination that will reveal planets, moon, and twilight glow beautifully balanced. View low light digital images on this week's web StarWatch at the address found below.
DIGITAL CONJUNCTION: Standing near the Rainbow Room restaurant at Wahweap, Arizona on Lake Powell, this spectacular planetary conjunction concluded on the morning of July 19, 2001. This time is 4:10 a.m. The moon and Mercury (see inset) are just rising. Above, and to the moon's right, is Jupiter. Continuing the arc upward finds Venus, the brightest star-like object in the photo, and then Saturn. All of the other dots are bona fide stars recorded in this 16-second digital image using a tripod mounted Kodak 290 camera. Paint Shop Pro was used to manipulate the image. Gary A. Becker photo... MOONLIGHT WAS USED TO DIGITALLY record this photograph of former Allen student Brandon Velivis at Chaco Culture National Historical Park, near Nageezi, NM in June 2001. The image was snapped with a tripod mounted Kodak 290 digital camera using a 16 second exposure and was enhanced by using Paint Shop Pro. More digital images can be found in the July 2001 StarWatch series of articles. Gary A. Becker photo...
264 SEPTEMBER 16, 2001: Is Pluto a Planet?: When Clyde W. Tombaugh, discoverer of Pluto, died on January 17, 1997, there was a quiet controversy going on among professionals. Was Pluto a planet? Ever since Tombaugh's extraordinary detection in 1930, Pluto had been at odds with the rest of the solar system family. Pluto orbited the sun at the greatest angle to the plane of the solar system, and it had the most oval-shaped orbit of any planet. As the years passed, continued reanalysis of Pluto's size revealed that it was smaller than Earth's moon, and its composition was a mixture of rock and ice, more like the moons of the outer planets than any planet itself. Even though a satellite was discovered orbiting Pluto in 1978, many astronomers still had uncomfortable feelings about Pluto. Then in the late 1990s, with improved technology, observers began finding dozen of small Pluto-like bodies orbiting the sun. An American, Gerard Kuiper, had predicted these objects in 1951 as a consequence of early solar system formation. As these distant rock and ice bodies accreted beyond Neptune, billions of years ago, the huge spaces between them made it improbable that further collisions would consolidate them into larger planets. But all of these Kuiper Belt objects were smaller than Pluto's moon, Charon, so Pluto's defense as a planet still remained intact. In the meantime, the International Astronomical Union, the worldwide governing body for astronomical nomenclature, has still continued to maintain Pluto's planetary status. Then this past summer the largest Kuiper Belt object was found to date, an object bigger than any of the asteroids orbiting between Mars and Jupiter. The debate to declassify Pluto gained a much stronger scientific footing, as the story continues next week.

265 SEPTEMBER 23, 2001: Pluto Reclassified?: Pluto is the oddest planet of the solar system. Its orbital parameters are the strangest, its composition is different, and it is the tiniest of all the planets. The strangeness of Pluto has led some astronomers to believe that Pluto should be reclassified as a Kuiper Belt object, condensations of rock and ice which never made it to planetary status. The debate has had an emotional and a rational forum. On the side of emotion has been the seven-decade acceptance of Pluto as a planet, and a genuine feeling of empathy and respect for Clyde W. Tombaugh, the farm boy turned astronomer, who through tenacity and perseverance made the discovery. I met Tombaugh and talked with him at length about his finding 10 years before his death. He must have told his story of discovery thousands of times to hundreds of thousands of people. But the excitement was still there in his quivering voice as he recited it to me again. I felt a genuine connection to this fellow explorer of the heavens. The rational argument is simple. Pluto just doesn't fit into the planetary landscape, and there are now over 400 new objects found mostly beyond Pluto, which are very Pluto-like. The solution would be to declassify Pluto as a planet and make it the first Kuiper Belt discovery. The basic operating rule of science is also very simple. Observations dictate theories. If the observations change, so must the theory. With the detection of 2001 KX76, a Kuiper Belt object larger than Pluto's moon Charon, in May of this year, the tables may be turning against retaining Pluto as a planet. But having looked into Tombaugh's sparkling eyes as he told me about his epic story of discovery, that change if it does occur, will be a difficult one for me to accept.

266 SEPTEMBER 30, 2001: The WE Method for Finding Directions