Messier 9 is a globular cluster located in the constellation Ophiuchus. It is approximately 25,000 light-years away from Earth and is one of the closest globular clusters to our solar system. Messier 9 contains hundreds of thousands of stars, tightly packed together, and is estimated to be around 11 billion years old. Discovered by Charles Messier in 1764, Messier 9 is designated as M9 in the Messier catalog. It has a diameter of about 100 light-years and is notable for its relatively high concentration of stars in its core. Observations of this cluster provide valuable insights into the formation and evolution of globular clusters in the universe.