Contents

02 December 1988
Vol 242, Issue 4883

About The Cover

A archival Kitt Peak National Observatory 4-meter telescope color optical picture (top) and a color infrared picture (bottom) of Messier 17, a region of vigorous star formation. The infrared picture is a composite of images made through 1.2-mircrometer, 1.65-mircrometer, and 2.2-mircrometer filters, colored blue, green, and red, respectively, and represents how Messier 17 would appear if the eye responded to infrared radiation. See page 1264. [The infrared picture was made with the Kitt Peak National Observatory 2.1-meter telescope by I. Gatley, D. L. DePoy, and A. M. Fowler, National Optical Astronomy Observatories, in collaboration with Charles Lada, University of Arizona]