''' '' SATURN'S STUDENTS'
SCIENCES '' ''' : MUSIC
MUSIC FROM SATURN'S HEART : !WOW!. Saturn's interior turmoil creates waves in one of its rings that scientists can decode. Saturn's key rings are not just visually wondrous.
Saturn, seen by the Cassini spacecraft's wide-angle camera in 2017. Saturn core makes 60 percent of the planet's radius and has 53 times the Earth's mass, but it is not solid.
Saturn's key rings are not just visually wondrous. One of them also records a beautiful planetary soundtrack.
The planet's interior, concealed beneath a shroud of mostly hydrogen gas, convulses. This causes shifts in the local gravity field, which pulls at particles in Saturn's broad C ring and makes them dance. These idiosyncratic movements can take the form of spiral waves, and distinct sets of waves reveal characteristics of Saturn's interior.
Put another way, Saturn is an orchestra. Different notes show up on the C ring, like those on sheet music. Scientists can read these notes, hear the music and identify the individual instruments and musicians performing - all without ever seeing the orchestra itself.
Using data from the NASA Cassini spacecraft mission, which ended in 2017, scientists have listened to and deconstructed a variety of symphonies in Saturn's C ring over the years.
Now, two researchers from the California Institute of Technology - Christopher Mankovich, a planetary scientist, and Jim Fuller, a theoretical astrophysicist - have decoded enough of this music to hear the sounds of one of Saturn's most puzzling features : its core.
According to this paper, published this month in the journal Nature Astronomy, the core is colossal : It makes up 60 percent of the planet's radius and is 55 times the mass of Earth.
And unlike the ordered solid clump of metallic, rocky or icy matter found within other worlds, Saturn's core is an amalgam of assorted rocks and ice mingling with a fluid metallic form of hydrogen.
The findings bring researchers closer to understanding how Saturn - and other gassy behemoths like it, including Jupiter - was born.
The geologic viscera of Earth, the moon and [ most recently ] Mars were mapped out with seismometers, instruments that record the journeys of seismic waves moving through the planet and behaving differently as they through mechanically different layers.
Saturn, lacking a solid surface, makes this sort of detective work impossible.
Orbiting spacecraft can roughly map out a gassy planet's internal layer cake structure by detecting subtle changes in gravity.
But Saturn's core has such a weak effect on the planet's gravitational field that this trick cannot be used to visualize it precisely. Fortunately, the shimmering of Saturn's C ring has unveiled what traditional techniques cannot.
Over the past three decades, scientists have been observing the ring's strange spiral waves through imagery from both the Voyager missions and Cassini. And they ultimately reasoned that those spirals are being caused by gargantuan oscillations within Saturn. ''They're just constant quakes that exist everywhere on the planet,'' Dr. Mankovich said.
It is a technique known as ''kronoseismology,'' ''kronos'' being the Greek word for Saturn and ''seismo'' pertaining to shakes.
In 2019, it was used to solve another puzzle : How long is a day on Saturn ?
[ About 10 and half Earth-hours. ]
Kronoseissmology is what showed that the core is made up of not only rock and ice but also the fluid metallic hydrogen, which was previously assumed to be a separate layer. Rock and ice are more concentrated at the center, and there is more fluid metallic hydrogen at the outer edges, but throughout, everything is mixed in a chaotic cocktail.
Despite the technique's success, scientists still don't know what is causing the core to oscillate and create those spiral waves in the C ring.
Earth resonates like a bell when it is rocked by powerful tectonic temblors. ''But Saturn is fluid, so where are the quakes?'' asked Mark Marley, a planetary scientist at the University of Arizona and an early trail - blazer of of kronoseismology who was not involved with the work.
The orchestra's musicians may finally be known, but the hunt for its elusive conductor continues.
The Honor and Serving of the Latest Global Operational Research on Planetary Sciences, continues. The World Students Society thanks author Robin George Andrews.
With respectful dedication to the Scientists, and then Students, Professors and Teachers of the world. See Ya all prepare and register for Great Global Elections on The World Students Society : wssciw.blogspot.com and Twitter - !E-WOW! - The Ecosystem 2011 :
Good Night and God Bless
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