September 1998 IssueWHERE: AT EXPLORIT Science Center, 3141 5th Street, Davis. |
CLUB EVENTS: Come to our meeting Saturday 26, at 8:30 where, in addition to views of the night sky, we will have a program on "The Problem of Light Pollution". We will see a slide show published by the Astronomical Society of the Pacific for the International Dark-Sky Association ("IDA)", which recently observed its 10th anniversary. This is the first part of a two part unit on (1) what is light pollution and (2) what can be done to curb it. At the meeting we will also view the Moon, Jupiter, Saturn, Uranus and Neptune, weather premitting. Anyone who can easily find the constellations Pisces and Aquarius is especialy encouraged to attend! Photon Torpedoes. Light pollution is light that is directed to places, including the sky, which are not intended to be illuminated by the light source. Laws to reduce the impact of light pollution have been adopted by New Jersey and Maine, the city and county of San Diego, the cities of Los Angeles and San Jose, and the Arizona cities of Flagstaff, Tucson, and Tempe. At one time light pollution addressed only the amount of light directed into the sky. But the topic has recently been broadened to include the notion of light trespass and nusiance glare from neighboring light fixtures. It also includes the efforts of improving visibility by reducing glare from strong lights ("glare bombs") when such glare is blinding, disabling or discomforting toothers. Virtually all pollution problems with lighting can be reduced by using more efficient lighting fixtures. Efficiency does not necessarily mean converting all outdoor lighting to orange low-pressure sodium lamps. It means using sound lighting design practices and using "cutoff" fixtures to reduce stray lighting, reduce energy consumption and save money.
More information may be found in the September 1998 issue of Sky and Telescope
magazine. The IDA site itself is very thorough
and it can be viewed at www.darksky.org/~ida/ The group represented a variety of people and interest levels. Some were new to the hobby and were interested in comparing the various telscopes and interviewing the regular attendees to learn more about astronomy. Some attendees were experts in telescope construction; eager to share their experiences and insights gathered through years of observing and building telescopes. Participants arriving at the airport site before 7:00 p.m. tended to park their cars and campers in one of two rows. The high-tech, motorized telescopes dominated one row and the Dobsonians occupied the outside row. I wondered if this division reflected differences in philosophy regarding the use of computers and CCDs, but one of the computerized telescope owners pointed out that the main reason was that row of computerized telescopes was closer to the electric power outlets. Alvin and a small group of friends were devoted to visual observation of faint objects, especially galaxies. One of the observers was from Winters, another lived in Sacramento. That night they would all be using dobsonian telescopes of 16 to 18 inches in diameter for viewing objects so faint that to my untrained eye they were invisible in the eyepiece. Besides good eyesight and a trained eye, I discovered that success in this field of amateur astronomy requires good pre-observation planning, a dark sky and good optics. I was impressed with the amount of planning and organization. An observing session is carefully planned with special maps of areas to be examined and, sometimes, forms to be completed while an observation is fresh in one's mind. Alvin has compiled nearly 10 volumes of observation data on galaxies and other objects. Visually observing faint objects such as galaxies also requires a very dark sky. Our group was very pleased with the dark sky this night, which many observers said was one of the best of the year at Blue Canyon. The sky was full of stars to the horizon-except for some light fog near the direction of Sacramento. The Milky Way was a shimmering veil across a star-studded sky field, the great galaxy in Andromeda was easily glimpsed with the unaided eye, and I observed several meteors as well. Good optics are also important for deep sky observing. One of the attendees had bought a tool that uses a laser to help align the mirrors in telescopes, and the dobsonian telescope owners who were present at the party were enthusiastic about its ease of use and accuracy. Precise alignment is important for this work because every photon is needed to see the faint objects. By 2:00 a.m. many of participants were preparing to leave or had gone home. Many would remain on site camped in vans or in enclosed pickups. Some would sleep in trailers with all the amenities of home. We left the site then, too. Approaching the bright glow of Sacramento I was aware of leaving a splendid natural night sky and entering an environment of dazzling artifical light. For a few hours I had been privileged see the "true" sky--the night sky as it had appeared until just 100 years ago. At night our cities now resemble enormous domes of light. Much of this light serves no purpose, but is the result of inefficiencies in outdoor illumination. How unfortunate for us and for future generations if these expensive and growing light domes isolate finally us from the mystery and haunting beauty of the true night sky where, indifferent to humankind, stars, meteors, planets and comets, shine fiercely against the blackness of space. ------------------------------------------------------------------- Hot night-Cool Shower. This Club's Perseid Meteor Shower Party at Fairfield Elementary School on Wednesday August 12, was attended by approximately 50 avid watchers. We were not disappointed as several bright meteors steaked across the sky every hour. This rate was approximately what we've observed the last couple of years.
The party began with a wonderful view of the Mir space station and one of
its supply ships. Around 9 o'clock an attendee asked Tim Feldman when the
Mir was going to appear. As if on cue, the ship appeared as a very bright
"star" moving from the northwest to he southwest. Preceeding the Mir was a
fainter "star" - its supply ship. On a lighter note, this year's party was
notable for the excessive heat (well in the nineties around 7 o'clock) and
by the flashing caution lights on a road grader that had been parked in the
west field adjacent to the playground. Thanks to Tim for handling questions
from the attendees and to all who brought their telescopes to share views of
the beautiful (and warm) summer sky.
The Astronomy Club is hosted by Dennis Smith with the assistance of Tim Feldman and other eager astronomy buffs. The club is for everyone - adults, children, knowledgeable or ignorant. Come to listen, look and learn, or to share your expertise or experience.
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