When a spacecraft goes where none have gone before, a few surprises turn up. As the Cassini spacecraft prepared to make its second loop through the narrow gap between Saturn and its rings today, scientists released more information about its first-ever pass through that uncharted region last week. Cassini researchers had expected that the spacecraft would encounter some diffuse dust, but the data shows the gap to be surprisingly dust-free.
"The region between the rings and Saturn is 'the big empty,' apparently," said Cassini Project Manager Earl Maize from NASA’s Jet Propulsion Laboratory in a statement. "Cassini will stay the course, while the scientists work on the mystery of why the dust level is much lower than expected."
While the lack of dust particles is puzzling, scientists are nevertheless quite excited, because this means the spacecraft has a better chance of surviving the remaining 21 passes before the end of the mission in September of this year. Cassini is running out of fuel, and will be intentionally crashed into Saturn so that it doesn’t accidently contaminate a potentially habitable moon such as Enceladus or Titan.