In astronomy, perhaps more than any other science, the cliché is true: A picture can be worth a thousand words. Unfortunately, with the illustrations in some astronomical textbooks, a picture can sometimes require a thousand words. And for beginning or inexperienced instructors, the worst thing can be that a picture may deserve a thousand words, but the instructor has only 50 words at his or her disposal.

Even for experienced instructors, unless the image happens to be in one’s own area of expertise, it can sometimes be difficult to appreciate or convey the full significance of a modern deep-sky photo, radiograph, or satellite multicolor composite image.