Assertion: lightning | /r/HasProperty | triggered
Facets:
value: by launching specially designed rockets
type: MANNER
value: artificially
type: MANNER
Source sentences:
text: Lightning can be artificially triggered by launching specially designed rockets that trail long wires which serve as pathways for lightning flashes to occur.
text: There, it was found that lightning in the plume was only triggered if temperatures fell below -20C, which implied the formation of ice was significant, because this is the temperature at which the supercooled water droplets freeze in the air.