28 ASTRONOMY • SEPTEMBER 2017
IT’S BEEN A WILD RIDE.
NASA’s Cassini Saturn orbiter has broken
just about every record in the planetary
encounters book. By the end of its first
decade in 2014, the spacecraft had logged
206 orbits, taken 332,000 images, carried
out 132 close f lybys of Saturn’s moons, dis-
covered seven of its 62 moons, and generat-
ed 3,039 science papers. Cassini’s powerful
engines and f lexible software enabled f light
engineers to redesign the mission to take
advantage of unplanned studies at geyser-
spouting Enceladus and methane-soaked
Titan. And its extended mission has car-
ried those numbers into a second decade of
exploration and discovery.
But all good things must come to an
end. On September 15, Cassini will meet its
doom in a fiery trail through the clouds of
From grazing Saturn’s rings to disappearing into its
swirling atmosphere, this spacecraft’s final days,
hours, and minutes will be fruitful ones.
by Michael Carroll
Cassini’s
Grand Finale
20 years in the making
NASA/JPL/UNIVERSITY OF ARIZONA/UNIVERSITY OF IDAHO CASSINI IMAGING TEAM, SSI, JPL, ESA, NASA
The saturnian moons Titan (left) and Enceladus (right) could support life, whether in their
past, present, or future. Cassini’s fiery end is a deliberate gesture to prevent unwanted
contamination of these worlds with Earth organisms. During its time in orbit around Saturn,
Cassini returned unprecedented views of these moons, including the first look beneath Titan’s
hazy atmosphere at the surprisingly Earth-like terrain below.Cassini has offered never-before-seen views of the saturnian system, providing researchers with a more comprehensive picture of the planet’s
atmosphere, ring system, and moons. This breathtaking portrait created by amateur image processor Gordan Ugarkovic combines 12 images
taken by the spacecraft in October 2013. NASA/JPL-CALTECH/SPACE SCIENCE INSTITUTE/G. UGARKOVIC