Cassini Spacecraft's Ring Dive Yields Saturn Surprises

Cassini Grand Finale Ring Dive
Artist’s illustration showing NASA's Cassini spacecraft heading toward the gap between Saturn and its innermost rings. The probe plunged through this gap for the first time ever on April 26, 2017. (Image credit: NASA/JPL-Caltech)

The Cassini spacecraft spotted strange atmospheric structures during the first of its 22 dives between the rings and the gas body of Saturn — the planet it has studied up close since 2004.

Cassini is in the last few months of its extended mission at the gas giant before making a suicidal plunge into Saturn's atmosphere in September. Until then, Cassini's dives into the uncharted region of Saturn will show scientists more about the structure of its rings and its atmosphere.

"These images are shocking," Kevin Baines, a science team member for Cassini's visible and infrared mapping spectrometer, said in a Facebook Live event Thursday (April 27). The event was held at the NASA Jet Propulsion Laboratory's mission control room in California, which is called the Space Flight Operations Facility. [Closest Saturn Pics Yet Snapped During Daring Dive (Video)]

NASA researchers said that, over the course of its dive between Saturn and its rings on April 26, the Cassini spacecraft has caught images from Saturn's pole to its equator. (Image credit: NASA/JPL-Caltech/Space Science Institute)

"We didn't expect to get anything nearly as beautiful as these images," Baines added. "All of the different structures we see on them are just phenomenal."

Showing pictures on a nearby television screen, Baines pointed to the "belly button" of Saturn, which is its north pole. Nearby were little clouds — "curlicues," he called them — with structures that scientists are still trying to understand.

Another picture showed a small cloud, which Baines nicknamed a "little car" because it runs around the perimeter of the hurricane-like hexagon at Saturn's north pole. While the region inside the hexagon is calm, the cloud — only a short distance away — zips along at a speed of around 300 mph (480 km/h). Its movement is still poorly understood.

NASA's Cassini spacecraft grabbed this raw image of a "giant hurricane" in Saturn's atmosphere during its first dive between Saturn and its rings on April 26. (Image credit: NASA/JPL-Caltech/Space Science Institute)

Mysteries of Saturn remain

Although Cassini has been at Saturn for nearly 13 years, there are still some basics that scientists are eager to know. Baines said he would love figuring out how long a day is, which is difficult to measure on a planet with no surface. Linda Spilker, the Cassini project scientist, added that it would be useful to know the "seed" from which Saturn was formed — the solid core the gas giant built up around as the planet matured.

While it's unclear if those long-standing mysteries will be solved, researchers expect to solve other ones during the ring dives. One of the dives will measure the composition of the rings using Cassini's cosmic dust analyzer. While 99 percent of the rings is made up of water ice, the remaining 1 percent's composition is uncertain; some possibilities include iron, silica, organics or a mixture, the researchers said.

Baines and Spilker also said they're hoping Saturn will produce some stormy weather in the coming months, so that Cassini can look at storm features from up close before diving into the planet.

When the spacecraft made contact with Earth again after its dive it reported that it was in excellent health, said spacecraft operations chief Julie Webster.

See more

"The spacecraft is perfect, as always," she said. "Everything came in just right down the middle. We weren't one telemetry point off; [there wasn't] anything we didn't expect last night. It was perfect right from the very beginning."

The researchers added that some of Cassini's last views before diving into Saturn will include the orange moon of Titan — which it just flew by for the last time last week — as well as the icy moon of Enceladus, and Earth itself.

Follow Elizabeth Howell @howellspace, or @Spacedotcom. We're also on Facebookand Google+. Original article on

Join our Space Forums to keep talking space on the latest missions, night sky and more! And if you have a news tip, correction or comment, let us know at:

Elizabeth Howell
Staff Writer, Spaceflight

Elizabeth Howell (she/her), Ph.D., is a staff writer in the spaceflight channel since 2022 covering diversity, education and gaming as well. She was contributing writer for for 10 years before joining full-time. Elizabeth's reporting includes multiple exclusives with the White House and Office of the Vice-President of the United States, an exclusive conversation with aspiring space tourist (and NSYNC bassist) Lance Bass, speaking several times with the International Space Station, witnessing five human spaceflight launches on two continents, flying parabolic, working inside a spacesuit, and participating in a simulated Mars mission. Her latest book, "Why Am I Taller?", is co-written with astronaut Dave Williams. Elizabeth holds a Ph.D. and M.Sc. in Space Studies from the University of North Dakota, a Bachelor of Journalism from Canada's Carleton University and a Bachelor of History from Canada's Athabasca University. Elizabeth is also a post-secondary instructor in communications and science at several institutions since 2015; her experience includes developing and teaching an astronomy course at Canada's Algonquin College (with Indigenous content as well) to more than 1,000 students since 2020. Elizabeth first got interested in space after watching the movie Apollo 13 in 1996, and still wants to be an astronaut someday. Mastodon: