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Speaker 1: Welcome to brain Stuff from How Stuff Works, Hey, brain Stuff,

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Speaker 1: Lauren Vogelbam Here, humanity exists at a very special time

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Speaker 1: in our Solar System's history, the era of Saturn's rings.

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Speaker 1: In the next hundred million years, Saturn's rings will completely disappear,

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Speaker 1: and planetary scientists have realized that it acquired those rings

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Speaker 1: only very recently. During the Cassini missions final months at Saturn,

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Speaker 1: the NASA spacecraft carried out a series of daring orbits

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Speaker 1: through the space between the planet's cloud tops and innermost

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Speaker 1: edge of its rings. This so called Grand Finale signaled

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Speaker 1: that the end was nigh for the probe, and on

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Speaker 1: September it burned up in the gas giant's atmosphere, bringing

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Speaker 1: a spectacular thirteen years of science in Saturn's orbit to

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Speaker 1: a poignant close. The spacecraft was low on fuel, and

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Speaker 1: to avoid an accidental crash into what a Saturn's potentially

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Speaker 1: habitable moons, NASA had long ago decided that the best

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Speaker 1: way to dispose of the mission was to burn it

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Speaker 1: up in Saturn's upper atmosphere. The agency wanted to avoid

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Speaker 1: earthly contamination on these pristine alien environments. Before its fiery death, However,

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Speaker 1: Cassini took unprecedented measurements of the mysterious ring gap region

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Speaker 1: to reveal some surprising ring dynamics. The mission scientists expected

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Speaker 1: to detect some whispy elemental gases in this empty region,

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Speaker 1: Cassini's particle instrumentation found a smorgas board of elements and

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Speaker 1: molecules raining from the rings down to the planet's atmosphere.

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Speaker 1: They estimated around ten tons of material that's about nine

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Speaker 1: thousand kilos is falling onto Saturn from the rings per second.

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Speaker 1: That means that Saturn's rings will eventually disappear and will

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Speaker 1: have existed only for a short blip of Saturn's four

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Speaker 1: billion year lifespan. So far, researchers have used Cassini's ring

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Speaker 1: dives to estimate when Saturn acquired its famous rings. When

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Speaker 1: Cassini zipped through Saturn's ring plane, mission managers allowed the planet,

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Speaker 1: its rings and moons to gravitationally tug at these speeding spacecraft.

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Speaker 1: These extremely slight tugs resulted in tiny change is in

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Speaker 1: the probe's trajectory, which could be precisely measured. Those changes

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Speaker 1: allowed scientists, too, for the first time, make a very

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Speaker 1: good measurement of how much mass is holed up in

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Speaker 1: Saturn's rings. After analyzing the final set of orbits, However,

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Speaker 1: the extent to which Cassini's trajectory was deflected initially didn't

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Speaker 1: make sense. It didn't match the predictions by theoretical models.

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Speaker 1: It turned out the Cassini's motion was being additionally altered

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Speaker 1: by massive flows of material at Saturn's equator, inside its

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Speaker 1: thick atmosphere about six thousand miles or nearly ten thousand

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Speaker 1: kilometers deep. These massive flows are moving about four percent

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Speaker 1: slower than the visible upper atmospheric clouds, causing a gravitational

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Speaker 1: anomaly that wasn't predicted. Cassini Project scientist Linda Spilker of

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Speaker 1: NASA's Jet Propulsion Laboratory set in a statement, the discovery

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Speaker 1: of deeply rotating layers is a surprising revelation about the

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Speaker 1: internal structure of the planet. The question is what causes

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Speaker 1: the more rapidly rotating part of the atmosphere to go

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Speaker 1: so deep and what does that tell us about Saturn's interior. However,

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Speaker 1: with this normally partially explained, scientists were free to measure

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Speaker 1: the gravitational influence of Saturn's rings, and thus measure their mass.

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Speaker 1: The researchers estimate that the total mass of Saturn's rings

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Speaker 1: is approximately that of Saturn's moon Mimus. Considering Mimus is

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Speaker 1: two thousand times smaller than Earth's spoon, there certainly isn't

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Speaker 1: a lot of material in Saturn's rings. Scientists had previously

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Speaker 1: relied on density waves or ripples through the rings caused

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Speaker 1: by the motion of the sixty two moons in Saturn's

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Speaker 1: orbit to estimate ring mass. Although these estimates were also low,

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Speaker 1: astronomers have always assumed there was some kind of hidden

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Speaker 1: mass in large blocks of material that remained unseen. Now,

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Speaker 1: with the precision measurements made by Cassini's final orbits, we

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Speaker 1: know that there is no hidden mass. The lower the

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Speaker 1: mass of the rings, the younger they are, and because

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Speaker 1: they are predominantly made of ice, if they were older,

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Speaker 1: the ring material would have become contaminated by interplanetary debris

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Speaker 1: dulling them. In. Saturn's rings, as we're acutely aware, are

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Speaker 1: beautifully bright. Previous estimates of ring age have been far

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Speaker 1: ranging from four point five billion years the leftovers of

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Speaker 1: when Saturn itself was forming, to a few tens of

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Speaker 1: billion years, but with this new finding in hand, it

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Speaker 1: looks like the rings are very young, formed less than

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Speaker 1: one hundred million years ago and perhaps as recently as

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Speaker 1: ten million years ago. Where the rings came from remains

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Speaker 1: more of a mystery. It's possible that an icy object

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Speaker 1: from the Kuiper Belt or an arrant comet became entwined

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Speaker 1: in Saturn's gravitational field and succumbed to the planet's powerful tides,

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Speaker 1: was ripped apart and eventually ground down to create the

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Speaker 1: banded rings we know and love today. Although Saturn's rings

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Speaker 1: will be gone in a hundred million years, it doesn't

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Speaker 1: mean that our Solar systems ringed planet days are gone forever.

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Speaker 1: If Saturn can create them, there's little reason why Jupiter, Neptune,

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Speaker 1: or Uranus can't shred anice the object create another bright

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Speaker 1: ringed planet display in the distant future. Today's episode was

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Speaker 1: written by Ian O'Neil and produced by Tyler Clang for

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Speaker 1: iHeart Media and How Stuff Works. For more on this

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Speaker 1: and lots other bright topics, visit our home planet how

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Speaker 1: Stuff Works dot com. MHM