First launched in 1997, Cassini has been knocking around the outer reaches of the solar system for years, exploring Saturn and its moons, and it has made some interesting discoveries. Cassini’s foray into Saturn’s rings will be its grand finale. The spacecraft will dive into the gap between Saturn and its rings, loop around the planet’s poles, and take a closer look at Saturn’s idiosyncratic features and study the gas and dust particles that make up the rings.
The mission then will close with Cassini flying close to the planet’s surface and ultimately plummeting into Saturn’s atmosphere in a final suicidal act. By then, Cassini will be out of fuel, and scientists don’t want to take the chance that the spacecraft could somehow crash into one of Saturn’s moons — moons that might be habitable — so Cassini will be intentionally steered into the planet to go out in a blaze of glory.
Saturn’s rings were first seen by humans in 1610, when Galileo Galilei turned his telescope to the night sky, and they have been the object of wonder and fascination ever since. The final stages of Cassini’s two-decade mission will give us more information about the rings than we have ever had before. And it may answer some nagging questions, like whether the rings are the same age as the planet itself, or were they formed later? And are there small moons embedded in the rings that might explain their shape and configuration?
NASA’s unmanned space exploration program should be the source of pride to all Americans. Through countless missions to the inner and out solar system, it has added exposed our planetary neighborhood as a constantly surprising place, with potential sources of water, rich mineral deposits, and places that might conceivably harbor other forms of life. The Cassini mission is just the latest chapter in an ever-encouraging tale that shows that the human impulse to explore and discover still runs strong.