NASA's Hubble Space Telescope captured an image of Messier 3 on July 8, 2026. Messier 3 is a globular cluster, recognized as one of the Milky Way galaxy's most massive globular clusters.

Globular clusters consist of spherical collections of stars that are gravitationally bound. These star groupings are composed of ancient stars that originated at approximately the same time from a shared cloud of gas, resulting in similar ages for the stars within a given cluster. The stars formed together from the same material, which explains why their ages are so uniform across the cluster.

The Hubble Space Telescope image was credited to A. Sarajedini of Florida Atlantic University, in collaboration with NASA and the European Space Agency (ESA). Gladys Kober, affiliated with NASA and the Catholic University of America, performed processing on the captured image. Kober's work involved refining the raw data to produce the final visual representation of the cluster.

Roughly 150 known globular clusters are situated in the outer regions of the Milky Way. These clusters orbit the galactic core in the halo region. The origins of Messier 3 may involve a merger between globular clusters that occurred in the early universe. Scientists suggest such mergers could contribute to the large size observed in Messier 3 compared to other clusters.

Messier 3 contains hundreds of thousands of stars packed into a relatively small space. The density of stars in the cluster's core is significantly higher than in the surrounding galactic disk. This high density makes globular clusters distinct from open clusters, which contain fewer stars and are less tightly bound by gravity.