Cassini: The Grand Finale: Cassini Finds 'The Big Empty' Close to Saturn
https://saturn.jpl.nasa.gov/news/3034/cassini-finds-the-big-empty-close-to-saturn/
As NASA's Cassini spacecraft prepares to shoot the narrow gap between Saturn and its rings for the second time in its Grand Finale,
Cassini engineers are delighted, while ring scientists are puzzled, that the region appears to be relatively dust-free. This assessment
is based on data Cassini collected during its first dive through the region on April 26.
With this information in hand, the Cassini team will now move forward with its preferred plan of science observations.
"The region between the rings and Saturn is 'the big empty,' apparently," said Cassini Project Manager Earl Maize of NASA's JPL in Pasadena,
California. "Cassini will stay the course, while the scientists work on the mystery of why the dust level is much lower than expected."
A dustier environment in the gap might have meant the spacecraft's saucer-shaped main antenna would be needed as a shield during most future
dives through the ring plane. This would have forced changes to how and when Cassini's instruments would be able to make observations.
Fortunately, it appears that the "plan B" option is no longer needed. (There are 21 dives remaining. Four of them pass through the innermost
fringes of Saturn's rings, necessitating that the antenna be used as a shield on those orbits.)
Based on images from Cassini, models of the ring particle environment in the approximately 1,200-mile-wide (2,000-kilometer-wide) region
between Saturn and its rings suggested the area would not have large particles that would pose a danger to the spacecraft.
