December 8, 2015
An exciting chapter of space exploration history will come to a close as NASA's Cassini spacecraft makes its final close flyby of Saturn's active, ocean-bearing moon Enceladus. The spacecraft is scheduled to fly past the icy moon at a distance of 3,106 miles (4,999 kilometers) on Dec. 19 at 9:49 a.m. PST (12:49 p.m. EST). Although Cassini will continue to observe Enceladus for the remainder of its mission (through Sept. 2017), its next-closest encounter with the moon will be at a distance more than four times farther away. The focus of the Dec. 19 encounter will be on measuring how much heat is coming through the ice from the moon's interior -- an important consideration for understanding what is driving its surprising geyser activity, which Cassini discovered in 2005.