Messier 5 or M5 (also designated NGC 5904) is a globular cluster in the
constellation Serpens. It was discovered by Gottfried Kirch in 1702.
Spanning 165 light-years in diameter, M5 is one of the larger globular
clusters known. The gravitational sphere of influence of M5,
(ie. the volume of space in which stars are gravitationally bound
to it rather than being torn away by the Milky Way's gravitational
pull) has a radius of some 200 light-years.