It's been 25 years to the day since the world lost the great Carl Sagan. A man who created a "message to the universe” on a gold record to be carried by the Voyager Interstellar Mission, helped discover that Venus is warmed by greenhouse gases and made turtlenecks a staple.
Though it has been over two decades since Sagan died in 1996 from bone marrow disease, we are still thankful for the lessons he taught us and the legacy he left behind. In a 2014 Smithsonian story, Sagan's wife, Ann Druyan, recalled a porter from Union Station in Washington, D.C., refusing to accept payment from Sagan, saying, "you gave me the universe." And Sagan did just that with his 1980s series, Cosmos.
Sagan taught us many valuable lessons about the universe and even made some uncanny predictions about the future. Here are four things we thank him for.