Scientists solve planetary ring riddle

August 5, 2015, University of Leicester
In this simulated image of Saturn's rings, color is used to present information about ring particle sizes in different regions based on the measured attenuations of three radio signals. Credit: NASA

In a breakthrough study, an international team of scientists, including Professor Nikolai Brilliantov from the University of Leicester, has solved an age-old scientific riddle by discovering that planetary rings, such as those orbiting Saturn, have a universally similar particle distribution.

The study, which is published in the academic journal Proceedings of the National Academy of Sciences (PNAS), also suggests that Saturn's rings are essentially in a steady state that does not depend on their history.

Professor Brilliantov from the University of Leicester's Department of Mathematics explained: "Saturn's rings are relatively well studied and it is known that they consist of ice particles ranging in size from centimetres to about ten metres. With a high probability these particles are remains of some catastrophic event in a far past, and it is not surprising that there exists debris of all sizes, varying from very small to very large ones.

"What is surprising is that the relative abundance of particles of different sizes follows, with a high accuracy, a beautiful mathematical law 'of inverse cubes'. That is, the abundance of 2 metre-size particles is 8 times smaller than the abundance of 1 metre-size particles, the abundance of 3 metre-size particles is 27 times smaller and so on. This holds true up to the size of about 10 metres, then follows an abrupt drop in the abundance of particles. The reason for this drastic drop, as well as the nature of the amazing inverse cubes law, has remained a riddle until now.

"We have finally resolved the riddle of particle size distribution. In particular, our study shows that the observed distribution is not peculiar for Saturn's rings, but has a universal character. In other words, it is generic for all planetary rings which have particles to have a similar nature."

Most of the planets in the Solar System have smaller bodies, or satellites, that orbit a planet. Some of them, such as Saturn, Jupiter, Uranus and Neptune, additionally possess planetary rings - a collection of still smaller bodies of different sizes that also orbit a planet. It is likely that planetary rings also exist beyond the Solar System.

This is an artist concept of a close-up view of Saturn's ring particles. The planet Saturn is seen in the background (yellow and brown). The particles (blue) are composed mostly of ice, but are not uniform. They clump together to form elongated, curved aggregates, continually forming and dispersing. The space between the clumps is mostly empty. The largest individual particles shown are a few meters (yards) across. Credit: NASA

Large asteroids, such as Chariklo and Chiron, only a few hundred kilometres in diameter, are also surrounded by rings.

Professor Brilliantov added: "The rather general mathematical model elaborated in the study with the focus on Saturn's rings may be successfully applied to other systems, where merge, colliding with slow velocities and break into small pieces colliding with large impact speeds.

"Such systems exist in nature and industry and will exhibit a beautiful law of inverse cubes and drop in large particle abundance in their particle size distribution."

Explore further: Which planets have rings?

More information: "Size distribution of particles in Saturn's rings from aggregation and fragmentation." PNAS dx.doi.org/10.1073/pnas.1503957112

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14 comments

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Returners
1.4 / 5 (9) Aug 05, 2015
Are you serious?

I showed several years ago that this holds true for all astronomical objects.

If you want to impress me, try explaining why the rings remain in tact over cosmic time, even though the should be disrupted by countless close-encounters with much more massive objects, such as comets and dislodged asteroid.

A large comet passing orthogonaly through the ring system or else along the same plane as the ring system should disturb the gravitational balance and cause the rings to collapse, but this apparently has not happened in at least eons...but saturn is so much more massive than Earth that it should encounter large comets and large asteroids much more often than Earth does.
baudrunner
4.4 / 5 (8) Aug 05, 2015
A large comet passing through a ring system with objects up to ten meters in size, with objects' population being inversely proportional to size, would pass through with no adverse effects on the entire ring, which would stabilize over time. The rings are vast, and they are very porous to things passing through.
wduckss
1 / 5 (4) Aug 05, 2015
Neighboring particles and bodies in the ring have the same speed of movement in orbits. There is no classic collision. Small attractive force between particles combine them into larger chunks. The rings of Saturn are fully furnished expensive, with the active processes.
docile
Aug 05, 2015
This comment has been removed by a moderator.
Elmo_McGillicutty
1 / 5 (7) Aug 05, 2015
Gravitational equilibrium requires 3-D motion. As does charge equilibrium.
Orbital objects do not follow circular or elliptical paths.
Stabilized orbits usually have the helix period(pitch) equal to the orbit period. This is why most orbits look like ellipses.
Draw a 1 pitch helix on a doughnut.........it looks like an ellipse.

Modern science will keep you ignorant.
jonesdave
3.8 / 5 (13) Aug 05, 2015
Great to see all these geniuses, who know better than the published scientists, giving us their "hypotheses" here. Word of advice: publish it, or shut up. I'm sick of reading crap.
NIPSZX
1 / 5 (5) Aug 06, 2015
Space is almost magnetic.. Maybe the dark matter is similar to magnetism.
docile
Aug 06, 2015
This comment has been removed by a moderator.
NiteSkyGerl
3.2 / 5 (11) Aug 06, 2015
You want to impress us Returners? Terminate your posting on this site, WITH EXTREME PREJUDICE, and we'll be impressed. Otherwise, STFU!!!
NiteSkyGerl
3.4 / 5 (10) Aug 06, 2015
And that goes double for your sock puppet Benni!
NiteSkyGerl
2.3 / 5 (6) Aug 06, 2015
"Jonesdave3.7 /5 (6) 14 hours ago
Great to see all these geniuses, who know better than the published scientists, giving us their "hypotheses" here. Word of advice: publish it, or shut up. I'm sick of reading crap."

Then you'll have to confine yourself to a site that doesn't take money from conservative foundations to not delete tin-foil hat jobs' post- because being tin-foil hat jobs they are favorable to religion and hostile to controlling climate change. It's time for a class action against the owners. An "attractive nuisance" suit.
jonesdave
3.8 / 5 (10) Aug 06, 2015
Word of advice: publish it, or shut up. I'm sick of reading crap.
Publishing = make public. Done.


No it doesn't. If you had any idea what you were talking about (and nobody here actually believes you do), then you would put this crap in a paper, and get it published. Then we could all sit back and behold your genius. As it stands, you're talking shi*te.
big_hairy_jimbo
5 / 5 (1) Aug 09, 2015
Wonder if this cubic rule applies to rings/discs around stars from which planets form? Surely this kind of thing evolves with time, so the cubic rule is temporal?
docile
Aug 09, 2015
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