Motions of the Skies

 

            Men and women of ancient civilizations had no more sophisticated tools to observe the heavens than their eyes, and yet when they looked up at the night sky they saw more than most men and women of the modern age.  The difference is not the number of stars, of course, or even the street lights and smog of today  (although they don’t help), but simply a difference in awareness.  You have seen the stars and planets all of your life, but have you seen them march across the sky at night? Or watched the planets and the moon in their monthly dance? Or noticed Orion the Great Hunter chasing Taurus the Bull across the winter sky?  The ancients were very much aware of this celestial activity; it was intimately interwoven with their life cycles and religions.  Today the skies continue their endless movements but we seldom notice; even professional astronomers often lose the sense of romance in the nightly ballet.  The purpose of these labs is to get you in touch with the night sky and, hopefully, generate some of the awe that the ancients felt for the heavens above them.

            To do each of these labs, choose a convenient place where you have a largely unobstructed view of the east, south and west.  The north side of an east-west road, without too many large trees or bright street lights, would do nicely, for example.  You will be making numerous short (5 minute) observations throughout the semester, so convenience is important.  Standing at your observing site, make a careful sketch, on at least an 8x11 unlined sheet of paper, of the permanent object on the horizon from the west through the south to the east.  Houses, trees, chimneys and the like will be the marks by which you make your measurements.  Earth-bound objects shouldn’t take up more than the lower third of your page – leave the rest for the sky and stars.  Figure 1 on the next page is an example of what you might draw.  You will be using this sketch often throughout the semester so take some care.  Also, you will be using the same sketch for all three labs, so you might find it useful to make a few Xerox copies of it (at least one for each lab).

            One of the hazards of being an astronomer is clouds – and there isn’t much you can do about it.  So if you find that you can’t observe on certain nights when you had planned, just imagine what its like to fly to Arizona for four nights on a large telescope and do nothing but watch the raindrops.  (Yes, it does rain in the desert!)  Rest assured that your instructors will be sympathetic to such problems; do the best you can.