Published online by Cambridge University Press: 18 December 2014
The purpose of this chapter is to help new observers get started. (If you’re a seasoned observer, you may want to skip to the next chapter, though you should read the section on “Observing Tips” before you do.) It contains enough essential information to help you find a few Messier objects. There is no avoiding the need to learn sky directions, recognize the major constellations and their brightest stars, know how to use a star map, and understand how the sky changes with the seasons. You can teach yourself just about all these things with a star wheel, or planisphere. These special sky maps are inexpensive, fun and easy to use, and very educational. (Star wheels can be purchased at any nature store or planetarium gift shop.) To purchase the proper star wheel, you will need to know your latitude on Earth so you can determine which stars are visible from your location. Consult a world atlas at your local library. You could also use one of the more popular Apps available online, such as Star WalkTM.
Although anyone can enjoy this book, the following section on sky orientation and many references to sky directions throughout the book are targeted primarily for observers at mid-northern latitudes. Observers in the far south will not be able to see several of the most northerly Messier objects. Chapter 6, however, describes many southerly objects either missed or ignored by Messier. A good supplementary guidebook for southern observers is my Deep-Sky Companions: Southern Gems. Otherwise, the material in this book, especially the descriptive notes on the Messier objects, can be used by all.