Saturn's Rings
I'm sure you've noticed that the rings of Saturn happen to closely resemble the shape and grooves of a long-play vinyl record. What would it sound like if you had a massive record needle and PLAYED that record?? That's what I attempted to recreate in this recording. Obviously some concessions had to be made: the rings are technically circles where an LP is a spiral, and no needle could possibly be made to specifications, to start. So the data that is available requires a certain amount of interpretation. This audio recording uses all data available to us today about the rings of Saturn. We have been able to survey the rings under three conditions: visual, infrared, and occultation (which if you don't know what it is, you gotta look it up, it's amazing!). These three surveys are being read one pixel at a time in a right-to-left fashion (a la a needle on a record); the brightness information from each pixel is used to drive sound generators. The data is interpreted in these ways:
1. Visual - ISS photographs - this is the amount of material in the rings. The needle will be colliding with many millions of particles per second -- due to these random interactions the main sound we will hear is random vibrations - i.e. noise. The brightness of the photograph drives a low-pass filter -- the "brighter" the ring, the "brighter" the noise.
2. RSS - Occultation -- this is the thickness of the rings. This is all relative as even at its thickest point the rings are only a few meters thick. This likely would not produce an audible difference in a 2500km-long record needle, but in our case it drives a second pink noise filter that emphasizes the low frequencies at high brightness data.
3. VIMS - Infrared -- this is information about particle size and composition. Brightness data is used as grain onset timing. Red represents ice concentration while blue-green represents rock concentration -- that said, the rings are composed of 99.9% ice, so even the bluest colors on this survey would be audibly indifferentiable from red sections.
I hope you weren't hoping for beautiful chords or hidden messages... in the end though, reading a huge field of rocks with a record needle is going to sound like a field of rocks. The entire piece is 20 minutes long, as that is the length of a standard LP side. The rings of Saturn turn at 10 hrs per revolution, which means that an actual performance of this piece would take 277 days. (The outer rings are moving at 110,000km/hr though, so they're still moving pretty darn quick...) It ends up being a pretty nice sleep noise generator!
I discovered that a few reddit readers already posted about it a few years ago on this subreddit, so I thought I'd bring it back now that I made it happen! Shouts out to u/avech and u/Deinos_Mousike who started the post and who did a lot of very interesting math legwork for this project!
