Messier 15 is a globular cluster in the constellation of Pegasus. This globular cluster was discovered by "Jean-Dominique Maraldi" in 1746. M15 is about 33,600 lightyears from Earth, and 175 lightyears in diameter. It has more than 100,000 stars, 112 variable stars and 8 pulsars. M15 also contains "Pease 1", the first planetary nebula discovered in a globular cluster.