Alternate timeline(covers information from an alternate timeline)
Polaric ions were particles which could be used as a weapon or as a power source. They were extremely unstable, and could produce temporal effects.
Since the Chaltok IV disaster in 2268, research and use of polaric ions was prohibited in the Alpha and Beta Quadrants.
In an alternate timeline, when Makull's species' planet was ravaged by an explosion, differentially-charged polaric ions were left over from the detonation. (VOY: "Time and Again")