There’s a lot of waiting in science. Collecting and interpreting evidence demands skill and commitment, creativity and curiosity — and time. Though Saturn has been known since ancient times, Galileo first observed it with a telescope in 1610. He saw the rings, but didn’t identify them as such. Not until the 1650s did Dutch astronomer Christiaan Huygens report a flat ring around Saturn. The first mission to Saturn had to wait until 1973, with the launch of Pioneer 11. It took six more years before that craft arrived at Saturn, where it flew through the outer rings.
Fast-forward another several decades, and for the first time ever, a spacecraft is now diving between Saturn and its rings. It’s been more than four centuries since the rings were first observed, and nearly two decades since the spacecraft, Cassini, launched from Cape Canaveral. Later this month, Cassini will enter Saturn’s atmosphere — another first — as part of its final farewell, as described by astronomy writer Lisa Grossman. Another probe probably won’t return to the planet until sometime after 2030.