Assertion: sunspot's polarity | /r/HasProperty | sunspots change
Facets:
Source sentences:
text: From cycle to cycle, the polarities of leading and trailing (with respect to the solar rotation) sunspots change from north/south to south/north and back.
text: From cycle to cycle, the polarities of leading and trailing (with respect to the solar rotation) sunspots change from north/south to south/north and back.