An asterism is a distinctive pattern of stars lying within a constellation — or, in some cases, one made up of stars from two or more adjoining constellations. Undoubtedly the best-known and most easily recognized of all such grouping is the Big Dipper in the constellation of Ursa Major.
Contrary to popular belief, the Big Dipper is not a constellation itself, but rather an “asterism” or distinctive figure within a constellation — in its case, Ursa Major, the Great Bear of the heavens. And as such, it’s surely the most famous asterism in the entire sky! Perhaps you have one of those neat rotating star charts, like the Edmund Scientifics’ Star and Planet Locator (which has just been revised and printed on heavier stock than the original one). By turning the chart, you’ll see how the Big Dipper wheels around the north pole of the sky and that it’s at its highest in the heavens in spring — during the evening hours of April (and also May).
