A spatial disturbance was an astronomical phenomenon.
The Suliban cloaking devices could create spatial disturbances. One such disturbance was detected by Enterprise NX-01's sensors in April 2151, shortly before the ship lost power. A later analysis of that disturbance indicated a stealth vessel with a tricyclic plasma drive. (ENT: "Broken Bow")
In September 2152, Enterprise, under command of the Takret Militia, encountered spatial disturbances while heading into a plasma eddy. (ENT: "The Catwalk")
The coaxial warp drive created detectable spatial disturbances, as encountered by the USS Voyager in 2374. (VOY: "Vis à Vis")
In 2376, the Voyager detected a dark matter asteroid which created a spatial disturbance. (VOY: "One Small Step")