Sunday, June 30, 2013
Sure signs that the best time for stargazing is here: The days are getting shorter and the nights are getting longer.
Summer is finally here, and what could be better than sharing a lingering look into the universe with dear friends and family under a really dark, star-filled sky.
If you plan it correctly, you’ll create memories that will last a lifetime. Here are some things to consider in order to create a spectacular night out under the stars.
The weather is always a major concern. Clouds and rain are the mortal enemies of the Lawnchair. While skies may remain clear all day, an approaching front can only ruin your plans. It’s best to keep an eye on weather sites and track what’s in store for your area.
Summer also tends to see an increase in humidity. Early evening skies can often be a bit hazy. Fortunately, as the night wears on, this moisture dissipates, and typically by late evening and early morning, skies are primed for inspection.
The next consideration is location. If you live in the city, your backyard perhaps isn’t the best place to consider a night out under nature’s tapestry. Ideally, if you can get away from the city – perhaps as little as 20 miles or so – you should be able to find a nice, dark place to set up your Lawnchairs.
What constitutes a nice place depends on what you want to see. If you’re looking to capture some deep-sky targets via a telescope, then the darker the locale, the better.
You want to stay away from places where there are street lights, billboards and the worst light-pollution offenders, auto dealerships, shopping centers and malls. Even in rural communities these days, light pollution is becoming an issue and limiting the ability for amateurs and professionals alike to enjoy dark, clear skies.
Once you find your way to a dark sky, you want to be able to see as large a piece of sky as possible. A large, open field is ideal, especially if it’s on a hill providing panoramic access to each horizon.
However, there is also the concern that the horizon in the direction of nearby cities will be awash in a glow of light. So you have a choice of either setting up in a valley field, limiting your access to some of the low-horizon targets, or a hill where you may be inundated with extraneous light from far-off cities and towns.
Next on the list is the question of when is best to try such a feat. Well, as it is with city lighting, the moon can lessen the success of a wonderful night out.
There are good and bad times to observe. For instance, when the moon is rising full in the east, it will persist all evening and make finding and observing any deep-sky objects almost impossible. However, when you see that sliver moon in the early evening heading toward the western horizon, rest assured that the remainder of the night will provide crisp, dark skies to peruse at will.
This is also the stage in the moon’s cycle when it can be observed best. When the moon is full, it’s simply too bright to do any meaningful observing.
Throughout the first- and last-quarter stages of the lunar cycle, the light levels, though still bright, are easily managed, and viewing the moon is much easier and typically more rewarding. Viewing along the terminator, or the line of day/night separation on the moon, can provide some interesting sights through a pair of binoculars or a small telescope. Look for sun rays peeking through the mountaintops illuminating portions of the moon.
The moon is often a great starting point for an evening of observing. However, in July, the best times to avoid lunar glare that would spoil any deep-sky stargazing will be before the 15th.
Then there are the planets.
In mid-July, Saturn is the star of the show, floating in the south-southwest as the sky turns dark at just after 9:30 or so.
Then, by late July, Mars and Jupiter emerge from their stay with the sun and, on the early morning of the 23rd, they emerge in close conjunction above the eastern horizon just before sunrise. It’s a great opportunity to see and/or photograph these wonderful wanderers.
While there’s plenty to see in the skies this July, in August, an opportunity to view meteors in large numbers will begin with the Perseid meteor shower.
So, as you prepare the old Lawnchair for a busy summer, look for that ideal location that will ensure your stargazing adventure will be memorable and hassle-free. I’ll have more on the Perseids and summer’s best deep-sky targets next month. Until then, here’s wishing you all a great summer. Clear skies!
Gerry Descoteaux is the author of “The Lawnchair Astronomer,” a Dell trade paperback. He has been writing about astronomy for more than 25 years. He also played an integral role in the development of AOL’s pioneering distance education program known originally as the Online Campus, in addition to presenting astronomy courses. His online course, An Introduction to Astronomy, is available as a self-study program atwww.thelawnchairastronomer.com.
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