Messier 2 is a globular cluster in the constellation of Aquarius. It is located 5 degrees north of Sadalsuud, beta Aquarii. It shines at magnitude 6.6 and has an apparent size of 16 arcminutes. It is located 37,500 light-years from Earth. At that distance, it has a true size of 175 light-years in diameter, making it one of the largest known globular clusters. M2 is believed to be 13 billion years old and contains 150,000 stars, the brightest of which have evolved into red and yellow giants. Messier 2 was discovered by Jean-Dominique Maraldi in 1746. Charles Messier independently rediscovered it in 1760 and added it to his list of deep-sky objects. William Herschel was the first observer to actually resolve the cluster into individual stars in 1783.