Researchers measured a spectrum of light emitted by the rare and elusive ball lightning.
Lucky strike. The spectrum of a cloud-to-ground lightning strike and of the ball lightning it generated. The ball lightning is the white dot at the far left, and its spectrum is the slightly brighter band of colors at the foot of the irregularly shaped main lightning spectrum. (See video below.)
strike lucky or strike it lucky
to suddenly have a lot of unexpected luck
I arrived at 12.30 to give myself time to find a parking meter, but struck lucky immediately.