Close views show Saturn's rings in unprecedented detail
Newly released images showcase the incredible closeness with which NASA's Cassini spacecraft, now in its "Ring-Grazing" orbits phase, is observing Saturn's dazzling rings of icy debris.
Cassini is now about halfway through its penultimate mission phase—20 orbits that dive past the outer edge of the main ring system. The ring-grazing orbits began last November, and will continue until late April, when Cassini begins its grand finale. During the 22 finale orbits, Cassini will repeatedly plunge through the gap between the rings and Saturn. The first finale plunge is scheduled for April 26.
Some of the structures seen in recent Cassini images have not been visible at this level of detail since the spacecraft arrived at Saturn in mid-2004. At that time, fine details like straw and propellers—which are caused by clumping ring particles and small, embedded moonlets, respectively—had never been seen before. (Although propellers were present in Cassini's arrival images, they were actually discovered in later analysis, the following year.)
In contrast, the close views Cassini has begun capturing in its ring-grazing orbits (and soon will capture in its Grand Finale phase) are taking in both the backlit and sunlit side of the rings. Instead of just one brief pass lasting a few hours, Cassini is making several dozen passes during these final months.
|This image shows a region in Saturn's outer B ring. NASA's Cassini spacecraft viewed this area at a level of detail twice |
as high as it had ever been observed before [Credit: NASA/JPL-Caltech/Space Science Institute]
After nearly 13 years studying Saturn's rings from orbit, the Cassini team has a deeper, richer understanding of what they're seeing, but they still anticipate new surprises.
"These close views represent the opening of an entirely new window onto Saturn's rings, and over the next few months we look forward to even more exciting data as we train our cameras on other parts of the rings closer to the planet," said Matthew Tiscareno, a Cassini scientist who studies Saturn's rings at the SETI Institute, Mountain View, California. Tiscareno planned the new images for the camera team.
Launched in 1997, Cassini has been touring the Saturn system since arriving in 2004 for an up-close study of the planet, its rings and moons, and its vast magnetosphere. Cassini has made numerous dramatic discoveries, including a global ocean with indications of hydrothermal activity within the moon Enceladus, and liquid methane seas on another moon, Titan.
Source: NASA [January 31, 2017]