Figure 18-18: R I V U X G
Formation of a Star Cluster The star cluster M16 is thought to be no more than 800,000 years old, and star formation is still taking place within adjacent dark, dusty globules. Massive young stars in the cluster power red emission lines of the H II region (called the Eagle Nebula for its shape). The inset zooms in on three dense, cold pillars of gas with ongoing star formation. The pillar at the upper left extends about 0.3 pc (1 ly) from base to tip, and each of its “fingers” is somewhat broader than our entire solar system.

(Australian Astronomical Observatory; J. Hester and P. Scowen, Arizona State University; NASA)