Outer Planets Exploration — 2 museum-grade prints from the period. Voyager 1 launched 5 September 1977 and flew by Jupiter in 1979 and Saturn in 1980, returning images that defined public understanding of the outer solar system. The spacecraft crossed the heliopause into interstellar space in August 2012 — the first human-made object to do so. Voyager 2 is the only spacecraft to have visited Uranus and Neptune, flying by Uranus in January 1986 and Neptune in August 1989. The Neptune encounter revealed the Great Dark Spot and active nitrogen geysers on Triton — findings that remain unmatched by later missions.