Messier 68 (also known as M68 or NGC 4590) is a globular cluster found in the east south-east of Hydra, away from its precisely equatorial part.

His son John noted that it was "all clearly resolved into stars of 12th magnitude, very loose and ragged at the borders".

[8] It is one of the most metal-poor globular clusters, which means it has a paucity of elements other than hydrogen and helium.

The cluster may have been acquired in its gravitational tie to the Milky Way through accretion from a satellite galaxy.

Six of the variables are of the SX Phoenicis variety, which display short pulsating behavior.