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Cassini captures the moon carved on the rings of Saturn – Astronomy Now



A mosaic made up of images during the last Saturn orbits of the Cassini probe reveals new information on how the small Daphnis moon gravitates by gravitating the nearby annular material into undulating waves. Click on the image to enlarge. Image: NASA Space Institute / JPL-Caltech

NASA's Cassini mission ended in 2017 with a deliberate dive into the atmosphere of Saturn. However, the data and images captured during the last, closest, pass of the planet's rings continue to reveal new details about the composition of the system and how small moons gravitationalally sculpt the particles of the planet. 39 ring in textures and delicate patterns.

"It's like increasing the power level compared to what we could see in the rings," said Linda Spilker, Cassini project scientist. "Everyone has a clearer view of what is happening. The obtaining of this additional resolution has answered many questions, but there are still so many tempting ones. "

The research, published in the journal Science, does not apply only to the dynamics of the rings of Saturn. It also highlights how astrophysical disks evolve, including protoplanetary disks that give rise to whole solar systems.

"These new details on how moons carve rings in different ways open a window to the formation of the solar system, where records also evolve under the influence of masses embedded in them," said L & #. Principal author and scientist of Cassini, Matt Tiscareno of SETI. Institute in Mountain View, California.

In a spectacular mosaic, we can see the small moon of Saturn, Daphnis, encrusted in the rings. Its gravity erases an area known as the Keeler space, dragging three waves into the outer edge of the space. Wave ridges diminish in size as they move away from the moon as the ring particles interact and collide.

Close-up showing how the farthest ridge in the waves behind Daphnis decomposes as circular particles jostle in the gravitational wake of the moon. Image: NASA Space Institute / JPL-Caltech

The sculpture generated by Daphnis was already well documented, but the new analysis reveals several unpublished features, including thin strands of ring material that spread as the farthest ridges diminish and break. The images composing the mosaic were captured at a distance of about 28,000 km (17,000 miles) from Daphnis.

"This tells us that the appearance of the rings is not only a function of the amount of material available," Tiscareno said. "There must be something different about the characteristics of the particles, which can affect what happens when two annular particles collide and bounce back and forth. And we do not know yet what it is.

Cassini's visible and infrared mapping spectrometer revealed another mystery: it detected a surprisingly weak signal for water ice in the outermost ring A of Saturn, a highly reflective region believed to contain relatively uncontaminated ice bands. In addition, no organic compound was detected and no detectable amount of ice with ammonia or methane was detected.

"If organic matter was in large quantities, at least in the main A, B and C networks, we would see it," said Phil Nicholson, Cassini VIMS scientist at Cornell University. "I am not yet convinced that they are a major component of the main rings."


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