My favorite part (though you will need binoculars at least or a 4" telescope with 100x magnification): > When and where to look > The comet will be primarily

My favorite part (though you will need binoculars at least or a 4" telescope with 100x magnification): > When and where to look > The comet will be primarily a morning object all through September, well-placed for observation in the after-midnight and predawn hours. Currently, Giacobini-Zinner is located in the constellation of Auriga, the charioteer. In the nights that follow its closest approach, 21P will track on a southeastward trajectory against the background stars. On the morning of Sept. 11, the comet will reach a spot on the sky bordering three constellations: Auriga; Taurus, the bull; and Gemini, the twins. > Make a special effort to look for 21P during the morning hours of Sept. 15; on that date, it will cross through Messier 35, a beautiful star cluster in Gemini. Of M35, the 19th century British astronomer William Lassell wrote in the “New Handbook of the Heavens” (McGraw Hill, 1948), “It is a marvelously striking object. No one can see it for the first time without an exclamation.” > Walter Scott Houston, who wrote a column called “Deep-Sky Wonders” in Sky & Telescope magazine for nearly half a century, called M35 his “personal favorite open cluster.” In this cluster, faint stars form curves and festoons, with a reddish star in the center. This cluster will be the backdrop for 21P on the morning of Saturday, Sept. 15.