Taking the Broad View: Skywatching with your Naked Eyes
November 2009 :
2009 has somehow been officially designated as the International Year of Astronomy, coinciding with the supposed 400th anniversary of the telescope, certainly a highwater mark in the history of science and in humankind’s gradual delving into the mysteries of nature. I used the word “supposed” because I don’t believe we can know with certainty whether someone prior to Galileo (1564-1642) may possibly have used a rudimentary optical arrangement by which enhanced views of sky objects would’ve been made possible. If so, did the person actually see anything that his or her naked eyes alone could not reveal? I guess it’s a moot point, owing to the fame of Galileo and his first-in-history recorded observations made with a telescope that he fabricated and improved the design of, but did not actually invent. Perhaps Hans Lipperhey of Holland was the originator in 1608, as is widely believed. Maybe one of Lipperhey’s spectacle-making contemporaries developed the first telescope, or some unknown optics experimenter years or even decades before was the inventor – how can we be sure?
A fine treatment of this subject is given by astronomer Fred Watson in his 2004 book, Stargazer: The Life and Times of the Telescope, ISBN number 0-306-81432-3. Chapters 3 and 4 of this book feature some of the best coverage I’ve read anywhere on the fascinating early possible development of telescopic lenses. Also, there’s a splendid article by Raymond Shubinski in the August 2008 35th anniversary issue of Astronomy magazine on this question of the actual originator of the telescope. My point in this is that people have only been using optical devices for looking at sky objects for the last 400 years, which isn’t really all that long in the overall scheme of things, all the important telescopic discoveries and leaps in astronomy notwithstanding. Obviously, for untold thousands of years prior to Galileo’s first observations in 1609, those who looked up and out at the night sky did so only with their own eyes. After all, Tycho Brahe (1546-1601) managed to amass an astoundingly rich trove of celestial data based on naked-eye observations that were of a level of precision good to between 1-2 minutes of arc! Granted, he had the advantage of using the best instruments that had ever been available to an astronomer before and during his time, but a telescope was not among them. Tycho’s observations were recorded and compiled through a career spanning about 35 years. No wonder Johannes Kepler (1571-1630) couldn’t wait to get full access to all of Tycho’s hard-won data. Kepler was spared all the monumental observing work done by Tycho and, instead, was able to use existing data for his own mathematical and theoretical work on planetary orbits, in particular the orbit of Mars.
The majority of the currently-defined 88 constellations making up the whole sky were conceptualized and originated many centuries ago by people who saw the stars as they were naturally presented to one’s naked-eye vision, without any optical aid at all. In other words, they viewed the night sky as a sweeping, continuous panorama, quite unlike the tiny and highly-restricted patches of sky we commonly can see in the field of a telescope. True, binoculars show much more but still impose an inescapable limit to how large a segment of the sky we can view at one time.
I’m the sort of astronomer who often prefers taking the easy way out, even after driving 90 miles from my home south of Worcester, Massachusetts to Arunah Hill in the Berkshires, a beautiful site for observing and known to many who share our interests. Elevation near the summit is nearly 2,000 feet and the sky quality ranks among the very best anywhere in southern New England. For me, the easy way out means not even bothering to set up a scope or take out binoculars, heretical as that may sound to some of you. The grandeur of the entire night sky as seen only with my eyes is easily worth the trip, particularly in late summer when the best, most concentrated and luminous Milky Way star clouds decorate the sky. Even an all-night session does not grow tedious for the lack of optical equipment in such a place as Arunah Hill, although I’d have to admit that most amateurs would regard this as purposeless.
There’s an important reason behind my subject this month. I hope to change the minds of those who tend to not see any point in viewing the night sky for very long without doing so through the eyepiece of a telescope. There’s a different way of considering astronomy, a way that just might be surprisingly pleasant, easy, and rewarding for you. Sure, by all means enjoy your scope and related equipment—you’ve spent money to acquire such things and it’s obvious that numberless fine sights in the sky can only be revealed and appreciated by optical aid. The old saying about not being able to see the forest for the trees pretty much makes my point here, though. You are unnecessarily shortchanging yourself if you’ve come to believe that astronomy can only be enjoyed by viewing everything in the very limited confines of telescopes or binoculars. Your eyes don’t require any setup time, nor will they dew over on damp nights. (Fogged eyeglasses are another matter.) If there are too many mosquitoes or if it’s just too cold to warrant spending more than a few minutes outside, forget your optical gear and just use your eyes.
What can you really see this way? Well, what you saw and were impressed by as a child, before getting involved in all the things so many of us have wound up regarding as the “official” way to do astronomy. Pick out the constellations and asterisms that our ancestors knew, or train yourself to better identify them if you’re a bit rusty or are just starting out. Note the stars that stand out in color among the majority that appear just white. Look for a few of the better-known variable stars that brighten or dim noticeably, or others that disappear outright for long periods, then gradually reappear as if by magic. If you’re lucky enough to have access to fairly dark skies when a bright Moon is absent, follow the course of the Milky Way—it’s enchanted people since we first came about on Earth. Meteors and meteor showers can’t possibly be taken in by an observer having his or her eye glued to an eyepiece. Large, scattered star clusters (M7 in Scorpius or the Alpha Persei OB Association in Perseus) might seem a bit more alluring to the naked eyes than when glimpsed in instruments, possibly because you can see them at all, just as the ancients did minus any optical help.
It’s sometimes easy to fall into what might be called the “equipment trap”, whereby you end up endlessly fussing with lengthy setups and subsequently thinking you’re somehow obligated to concentrate solely on all your gear in order to view sky objects. Meanwhile, the entire sky above you can be seen immediately by merely looking up! Yes, we live in a modern, technical age that seems to so often be defined by the devices and material things that are the backdrop of our lives, but remember: If you had lived prior to 1609 and loved looking out at the night sky, you would’ve seen it just as everyone else down through history before you had seen the sky—with your naked eyes alone.
