Spacecraft offers a unique view of Saturn’s atmosphere
Some findings from NASA’s Cassini have been puzzling scientists — but that’s part of the fun, one JPL expert says.
One day our human descendants may be able to go sightseeing in the glorious Saturn system. Until then, we have Cassini.
A newly released video affords a view from the spacecraft as it flies over the hexagon-shaped jet stream on Saturn’s north pole and makes its way south.
The movie was taken April 26, during Cassini’s first pass through the previously unexplored region between Saturn and its innermost ring.
It begins with a view of the great, swirling hurricane-like vortex in the center of the hexagon.
As the spacecraft passes the boundary of the six-sided jet stream, it captures the linear features of this part of Saturn’s atmosphere in more detail than was ever possible before, said Linda Spilker of NASA’s Jet Propulsion Laboratory in La Cañada Flintridge and the project scientist for the mission.
Spilker said she was hopeful that images like these will ultimately help researchers to better understand this strange Saturnian feature.
“The hexagon is a puzzle we still haven’t figured out,” she said. “Most jet streams don’t have that shape, and they don’t hold the same shape for so long.”
Saturn’s unusual jet stream was first seen by Voyager more than 35 years ago, and it hasn’t changed much since then. It’s also enormous — two Earth diameters in width.
Over the course of the video, Cassini flies closer and closer to the planet, dropping from 45,000 miles to 4,200 miles above the cloud tops.
However, getting closer to Saturn didn’t translate to a better view.
“Going down, it got hazier and hazier and harder to see what’s going on,” Spilker said.
She added that the imaging team was planning to tinker with the camera settings to bring out the contrast for future dives.
Plans call for Cassini to make 21 more passes through this uncharted territory over the next four months.
After its final dive, on Sept. 15, Cassini’s 13-year mission to the Saturn system will come to an end.
Although its instruments are working flawlessly, the spacecraft is out of fuel.
To keep from accidentally contaminating two of Saturn’s moons, which have the potential to harbor life, Cassini will dive into Saturn’s atmosphere, where it will vaporize in a matter of minutes.
But until then, there is plenty of science left to do.
The spacecraft completed its second dive on Tuesday. A third, scheduled for next week, should give scientists their first opportunity to determine if Saturn has a rocky core, and how big it might be.
The spacecraft has already sent some unexpected findings back to Earth, including the discovery that there is even less dust between the planet and its rings than scientists expected.
“That’s the fun of going where no spacecraft has ever gone before,” Spilker said. “It’s always good to get something you don’t understand.”