StarWatch for the greater Lehigh Valley



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[Moon Phases]
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524    SEPTEMBER 3, 2006:   Photography by Moonlight
This week, the moon dominates the late summer nights, and becomes full on September 7. Two months ago as a volunteer astronomy interpreter, I was participating in full moon hikes at Bryce Canyon Nat. Park in SW Utah. Bryce has made a concerted effort to acquaint its visitors with the beauty of the park at night. On this particular evening, my friend, “Dark Ranger” Angie Richman, was leading a hike down the Queen’s Garden Trail. The sky was mostly cloudy as we headed toward the canyon rim. A few moments later, I spotted a slash of deep crimson as the moon appeared through thinning clouds. Fulfilling a self-promise, I had left my cameras behind so that I could observe the group dynamics. As the moon rose big and red above the cloud deck, people went bonkers. Out came dozens of digital cameras and within several seconds, flashes were popping like a miniature Fourth of July fireworks celebration. The group produced some very interesting photos despite the annoyances of the flashes which could not be avoided in the point-and-shoot cameras that were being used. As we continued our hike into the canyon, a higher and brighter moon illuminated the fins and silent hoodoos of the Bryce amphitheater. The sight was surreal, complete with flashes of distant lightning. I got the message. During the next two weeks whenever it was clear, I found myself taking pictures of Bryce by moonlight from the canyon rim. The images were mostly keepers. I mounted my camera on a tripod and attached a cable release to initiate the exposures smoothly. For the full moon I used 30 seconds at F/4.5, at an ASA of 800. See my images at the URL below. Pictures by moonlight are a whole new way of experiencing the night.

[Full Moon at Bryce Point]
Bryce Point by Moonlight:   There is no one around at 2:00 a.m. to spoil your photograph. This self-portrait was taken with a Canon D20 mounted on a tripod. The camera was set for a 10-second delay and triggered through an electronic shutter release. A super wide-angle, 10-20mm zoom lens was used at F/4.5 for this 30 second exposure. Notice the Big Dipper in the upper left-hand portion of the picture. The moon was one day past full. Photo by Gary A. Becker...

[Bryce Point by Moonlight]
Tropic, Utah glows under the light of a nearly full moon from Bryce Point in Bryce Canyon National Park. The lens and exposure setting were the same as the first image. Gary A. Becker photo...

525    SEPTEMBER 10, 2006:   Pluto Didn't Fit the Planetary Mold
Colleagues and students have been stopping me in the hallways and asking, “What has happened to Pluto?” It’s as if NASA and the European Space Agency just exploded this tiny ice and rock world into smithereens with their photon torpedoes and laser blasters. Someone suggested changing Pluto’s name to Snoopy; another individual said, “Pluto has simply gone to the dogs!” I jokingly said to a reporter that we’ll need to take a backhoe to our local Planet Walk in the Lehigh Parkway. WOW, I’m still receiving notes from friends about that one. Others have simply told me they will not accept the decision of astronomers demoting their beloved Pluto to a dwarf planet. Pluto, it seems, is more famous than ever amongst the public, but astronomers have been distancing themselves from this tiny world for decades because it just didn’t fit into the planetary landscape. It wasn’t like the four inner terrestrials—small, low mass, rocky worlds, and it surely didn’t fit the Jovian planets—big, high mass, and mostly liquid. Pluto’s path had the greatest tilt to the plane of the solar system, and its orbit was the most eccentric. It was unique until astronomers in the early 1990s began discovering scores of small Pluto-type worlds. Now the number of trans-Neptunian bodies is just over 1000 with 2003UB313 about 60 miles in diameter larger than Pluto. Something had to be done and that responsibility fell on the shoulders of the International Astronomical Union. If you consider that 2,500 voting members of the IAU attended the recent August meeting in Prague, less than 500 astronomers actually voted on the Pluto question. Although hotly debated by the public, professionals were really not overly concerned about Pluto’s fate.

526    SEPTEMBER 17, 2006:   Photographing Lightning
There is a problem with photographing lightning. It can kill you! The Weather Channel recommends that if you can hear thunder, you’re within striking distance. The National Park Service has the 30 second rule. If you see lightning and hear thunder within 30 seconds, seek shelter. Sound travels about one mile for every five seconds of elapsed time. At Bryce Canyon in SW Utah where I have been an astronomy interpreter for the last two summers, thunderstorms are plentiful, and they can form within minutes, leaving hundreds of tourists stranded in exposed areas. When storms approach from the east, they can march towards the canyon like a line of soldiers. Such was the case on the evening of Friday, July 21 when continuous lightning from five distant storm cells strobed the eastern flanks of Bryce. I photographed from Sunrise Point. My Canon D20 was tripod mounted and set on bulb. A cable release allowed me to trigger the shutter and lock it down so that I could capture multiple bursts. Because the storms were far-off, I used a zoom, 70-200mm telephoto lens stopped down to F/8 to bring the action closer. The lens distance was set to near infinity. My chip sensitivity was initially positioned at ASA 800, but as the storms drew nearer, it was reduced to 400. My exposure lengths varied from 30 to 90 seconds. After each photo was recorded, the camera automatically imaged the noise from the chip and subtracted it from the picture that had just been taken. While the chip noise was being recorded, I recomposed, if necessary, to other areas of the storm where activity was building. I was thus able to maximize my ability to capture multiple events. Go to the URL below and click on “This Week’s StarWatch” button to see the results.

[Bryce Lightning]
Photographing Lightning can be dangerous, so play it safe. If lightning produces thunder within a 30 second time period, you are in danger of being struck. A telephoto lens brought the action much closer than it actually appeared. In the image above, note the ridge fire (reddish glow, along the horizon to the left) that had been set by another strike. The photo below was a single event, while the last photo was at least three events recorded as a single image. Read the article above for specific details on how to safely photograph lightning. Digital images by Gary A. Becker...

[Bryce Lightning]

[Bryce Lightning]

527    SEPTEMBER 24, 2006:   Mercury to Transit the Sun in November
It occurs during the day, and it happens between 13 and 14 times a century in different parts of the world. That means we don’t get to see all of them. In those situations where we are correctly placed, cloudy skies will curtail successful viewing. You will need a properly filtered telescope or binoculars to see it. The last one that I observed was on November 10, 1973 during my second year as a teacher. Now in my 35th year, the possibility of seeing another similar event presents itself. On Wednesday, November 8, starting at 2:14 p.m. the smallest planet in the solar system, Mercury, will begin to transit, or cross in front of the sun. Many people along the East Coast remember the vivid scene as a crimson sun with the black dot of Venus emerged from the fog on the misty morning of June 8, 2004. Venus was seen against the extremely dim sun with the unaided eye. Transits of Mercury are less spectacular because the Messenger God is smaller and much farther away. Minimally, properly filtered binoculars will be necessary to enjoy this event. That means purchasing a glass or Mylar solar filter which will go on the front end of your telescope or binoculars. Solar filters or Mylar solar filters typed into your favorite search engine will begin your inquiry. Thousand Oaks Optical and Baader AstroSolar are reputable firms that can be counted upon to deliver quality front end filters that stop the sun’s radiation before it enters the telescope. Filters near the eyepiece are dangerous because they can heat up and break. Now is the time to plan for the Mercury transit on November 8, or consider visiting Dieruff High School to view the transit along with the ASD Planetarium’s StarWatch team of student and adult volunteers.

[Mercury Transits the Sun]

September Star Map

September Moon Phase Calendar