Last month we were discussing the issue of light pollution. A quick look at a composite, night-time satellite image of North America shows one result – we are currently wasting almost a billion dollars a year in the United States lighting the night sky from the ground! And, it’s not only wasteful, it’s not doing what it’s supposed to do for the people and the property at ground level. Indeed, poorly designed outdoor lights are detrimental of both security and property values.
According to the International Dark Sky Association (http://www.darksky.org) and the New England Light Pollution Advisory Group (http://cfa-www.harvard.edu/cfa/ps/nelpag.html) , here are some more reasons why you should care about good lighting:
Light trespass occurs when lighting installed on one property shines on neighboring property. It gives the area a trashy, honky-tonk appearance, reduces the neighbors’ privacy, and often interferes with sleep because it shines into bedroom windows.
Glare is when you see the bright bulb of a light fixture instead of the thing it is supposed to illuminate. It hampers vision, making pedestrians, cyclists, and drivers less able to see obstacles or security threats. If you can’t see, you are less safe, no matter how much you’re spending on lights.
Sky glow is created by the upward directed light as it scatters from clouds, buildings, billboards, and dust in the air. It makes it impossible to see clearly the night sky, washing out our view of the natural wonders which ought to be our heritage.
What can we do about it? First, don’t use more light than required for the task at hand. Aim lights so they don’t spill off the property, and don’t aim lights horizontally or upward. Choose shielded "full-cutoff" fixtures which keep light aimed where it’s needed, i.e. down. Install and test lights at night, so you can see what’s being illuminated. This will permit you to illuminate the ground without glare – you’ll be able to see the people, cars, and landscaping rather than dazzling, glaring lights. And, you can provide as much illumination with lower wattage bulbs because you are not sending half of it into the sky. When feasible, put lights on a timer so that they go off when they aren’t needed. Security lights should be on a motion detector circuit, which further activates them only when there’s someone in the area.
True, the initial cost of the fixtures may be higher than for a wasteful, poorly designed fixture. But, the long term costs will be far lower, paying the investment back many-fold.
Lunar phases for November: First Quarter on the 4th, at 2:27 am; Full Moon on the 11th, at 4:15 pm; Last Quarter on the 18th, at 10:24 am; New Moon on the 25th, at 6:11 pm. All times are Easter Standard – you should have set your clocks back on October 29th!
Planet viewing in the evenings is the best in several months. Venus gets higher in the evening twilight as the month passes. Jupiter and Saturn rise about an hour after sunset on the first, but each comes to opposition this month (Jupiter on the 27th, Saturn about a week earlier on the 19th). They will rise earlier each day, rising at sunset when at opposition, and then visible all night. Mars and Mercury are visible in the predawn, both to the east southeast.
This should be a good year for the annual Leonid meteor shower. Best viewing will be on the 17th after midnight. Since the Moon is approaching last quarter, interference from moonlight should not be a factor.
Our midmonth view of the sky, roughly three hours after sunset, finds the Andromeda Galaxy, some 2 million light years distant and the furthest object you can observe without a large telescope, almost directly overhead. You should be able to pick it out on a clear, moonless night without even binoculars. The light you see from this object left on its journey to your eyes when our ancestors were just coming down from the trees on the African savanna. The giant empty square of Pegasus is just to the southwest of Andromeda. The southern half of the sky is nearly empty of bright stars, save Fomelhaut low to the southwest. If you are in a light polluted area you’ll see very little in that direction, but take heart. Orion is rising to the east, Taurus and the Pleiades are playing host to Jupiter and Saturn, Castor and Pollux are rising, too. The winter sky is my personal favorite, rich in bright stars, recognizable constellations, and nearby fields of star formation.
Copyright 2000
George F. Spagna, Jr.