When the 17th century astronomer Giovanni Domenico Cassini
stared through a telescope at mighty Saturn, he knew he had found his life's great work. The planet was only just beginning to come into focus, in the metaphorical sense: The Dutch astronomer Christiaan Huygens had just recently revealed Saturn's rings and its first known moon, Titan. Over decades of study, Cassini went on to discover four of Saturn's moons
along with the so-called Cassini Division
between Saturn's brightest rings.
The astronomer's namesake--the Cassini space probe
--is now helping us learn about the ringed planet. The probe launched in late 1998 and traveled about 2.2 billion miles to reach Saturn; it entered the planet's orbit on July 1, 2004.
Since then, the spacecraft has visited many of Saturn's moons--including Titan, Iapetus, and Rhea--while giving scientists new insight into Saturn's atmosphere
and cloud patterns. Observations from Cassini, which is a collaboration between NASA, the European Space Agency, and the Italian Space Agency, have also illuminated the structure of Saturn's rings
This artist's rendering depicts Cassini's approach toward Titan, one of Saturn's 60+ moons. The spacecraft's field instruments observed Titan's northern region this past June.