Assertion: polar hexagon | /r/HasProperty | discovered by the voyager mission
Facets:
value: in 1981
type: TEMPORAL
Source sentences:
text: Saturn's polar hexagon was discovered by the Voyager mission in 1981, and it was revisited in 2006 by Cassini mission.
text: Saturn's polar hexagon was discovered by the Voyager mission in 1981, and it was revisited in 2006 by Cassini mission.