Assertion: twilight | /r/CapableOf | last at latitude
Facets:
value: within 9 degrees of either pole
type: LOCATION
value: for the entire 24 hours
type: TEMPORAL
Source sentences:
text: At latitudes within 9 degrees of either Pole, as the sun's angular elevation difference is less than 18 degrees, twilight can last for the entire 24 hours.