English: The first globular cluster to be added to the Messier catalog, M2 is located roughly 37,000 light-years from Earth in the constellation Aquarius. A globular cluster is a spherical group of stars that are bound together by their mutual gravitational attraction. M2 has a diameter of over 150 light-years and is one of the largest clusters of its kind. It was discovered in 1746 by the French astronomer Jean-Dominique Maraldi while he was observing a comet.

M2 contains over 150,000 stars. Most of the cluster’s mass is concentrated at its center, with shimmering streams of stars extending outward into space. It can be seen with the naked eye under clear, dark skies far from city lights.

For more information, visit: www.nasa.gov/feature/goddard/2017/messier-2

Credits: NASA, ESA, STScI, and A. Sarajedini (University of Florida)