A tracking device for automatically following a moving light source that is detectable in the presence of ambient light. A carrier platform including one or more radiant energy conversion devices and a sensor array is mounted to an upright support column with a universal joint. Three linear actuators, each having an associated light sensor, are equally angularly spaced about the support column with an upper end connected to the carrier platform with a universal hinge and a lower end connected to a floating base with a spherical hinge. The floating base is free to move axially but not radially of the support column. The actuator of a light sensor receiving a lesser amount of radiant energy retracts, and extends when receiving a greater amount of radiant energy. Each light sensor is moved in a stepwise manner, with a predetermined, limited number of steps used to define light source acquisition for tracking purposes.