The "Other" Horizon
Consider a situation where you've just bought a home in an area with reasonably dark skies (anyway, as dark as can be expected for this area). One of the first things you'd probably do is check the southern horizon to see if it's free of serious light pollution and that it's unobstructed. We think in terms of having a good view of the southern Milky Way and a clear shot at the planets as they wend their way along the ecliptic. Almost as a matter of course, our orientation tends toward the southern sky.
Yet consider that from where most of our homes are located, the southern sky is the most light polluted. In that direction lies the most densely populated part of the Chicago metropolitan area. However, the north contains some deep sky treasures too...along with a generally darker sky background.
Swing your scope toward the north, and when the Big Dipper is high (primarily in the springtime), you'll have a great shot at some of the best galaxies available to the amateur astronomer. Here are the constellations you'll see:
Going still deeper, in the following image we'll zoom in a bit and pull up objects of 12th magnitude and brighter - within reach of most amateurs' telescopes. (For this exercise, we're using the Home Planet computer program.) When we look at the area around Ursa Major, there are so many objects that the symbols overlap each other and the display becomes unreadable. But that's okay. The intent here isn't to show discrete objects, but to illustrate the profusion of targets that awaits you. Dig out your star atlas and plan your attack!
Roughly six months removed from the above image, a different sky stands well above Polaris. We have fall and winter constellations, with a profusion of open clusters. This time, our search is confined to everything brighter than 8th magnitude, which puts all these objects within the reach of not only the smallest telescopes, but good binoculars as well. The chart is still crammed full of overlapping symbols. Get out that star atlas again - a crowded northern sky awaits!Published in the May 2000 issue of the NightTimes