Star Cluster Messier 67 . ... Credit Copyright: Processing - Noel Carboni , Imaging - Greg Parker Explanation: Gathered at the center of this sharp skyview are the stars of Messier 67 , one of the oldest known open star clusters . In fact, though open star clusters are usually much younger, the stars of M67 are likely around 4 billion years old, about the same age and with about the same elemental abundances as the Sun. ... NASA Web Site Statements, Warnings, and Disclaimers . ...