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What Voyager Saw · The Infographics Show Podcast

• 0:10
  Speaker 1: Imagine staring at a photograph of a single speck of dust,
• 0:14
  Speaker 1: just kind of floating in a beam of light. Right now,
• 0:17
  Speaker 1: Imagine realizing that every human being who has ever lived, loved,
• 0:20
  Speaker 1: or died did so on that tiny speck. Yeah, I mean,
• 0:24
  Speaker 1: every war ever fought, every masterpiece painted, all of it
• 0:28
  Speaker 1: can fined to just a fraction of a pixel.
• 0:30
  Speaker 2: It really forces a kind of cognitive reset, doesn't it.
• 0:34
  Speaker 1: It absolutely does. It's like it strips away all that
• 0:37
  Speaker 1: terrestrial arrogance we walk around with it very day. Completely
• 0:40
  Speaker 1: Welcome to Beyond Infographics. I'm so glad you're joining us
• 0:43
  Speaker 1: on another journey today, and hey, if you enjoy the ride,
• 0:45
  Speaker 1: please take a second to rate Beyond Infographics five stars.
• 0:48
  Speaker 1: It really helps us out, It really does. So. Today
• 0:51
  Speaker 1: our mission is to explore a profound personal insight. I've
• 0:54
  Speaker 1: been wrestling with the idea that humanity's greatest, most enduring
• 0:58
  Speaker 1: legacy might not be down here on Earth, but rather
• 1:01
  Speaker 1: it's a pair of nineteen seventy spacecraft.
• 1:03
  Speaker 2: Yeah, the Voyager program Voyager one and two, launched way
• 1:06
  Speaker 2: back in nineteen seventy seven.
• 1:08
  Speaker 1: Exactly. We're gonna trace their path through the Grand Tour
• 1:11
  Speaker 1: of the outer Solar System, talk about the jaw dropping
• 1:14
  Speaker 1: planetary discoveries they made, the revolutionary camera tech that made
• 1:19
  Speaker 1: it all possible, and ultimately that philosophical awakening triggered by
• 1:23
  Speaker 1: a single photograph of a tiny blue dot.
• 1:26
  Speaker 2: And my personal hook into all of this. The thing
• 1:28
  Speaker 2: that just fascinates me isn't just the destinations they reached.
• 1:31
  Speaker 2: It's the boundaries they crossed. I mean, moving from the
• 1:35
  Speaker 2: Sun's protective plasma bubble and pushing out into the completely
• 1:38
  Speaker 2: uncharted territory of interstellar space.
• 1:41
  Speaker 1: It's mind blowing. Okay, let's unpack this because the sheer
• 1:44
  Speaker 1: scale of the Voyager program is well, it rewrote our
• 1:48
  Speaker 1: understanding of the cosmos. They launched in seventy seven to
• 1:52
  Speaker 1: capitalize on a rare planetary alignment, right.
• 1:55
  Speaker 2: Yeah, a geometry that only happens like once every one
• 1:58
  Speaker 2: hundred and seventy five years.
• 1:59
  Speaker 1: Yeah.
• 2:00
  Speaker 2: It allowed the probes to basically use the gravity of
• 2:02
  Speaker 2: one planet to sling themselves toward.
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  Speaker 1: The next, a cosmic slingshot exactly.
• 2:06
  Speaker 2: But before we even get to interstellar space or sling shots,
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  Speaker 2: we have to talk about how they actually saw anything
• 2:11
  Speaker 2: out there.
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  Speaker 1: This is the part that I love we're talking about
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  Speaker 1: nineteen seventy seven, the era of eight track tapes and
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  Speaker 1: rotary phones. Right, Yeah, How do you send a camera
• 2:20
  Speaker 1: system into the pitch black outer solar system and capture
• 2:23
  Speaker 1: images that we are literally still analyzing today.
• 2:27
  Speaker 2: You do it with an astonishing level of well mechanical
• 2:30
  Speaker 2: and electrical engineering. Yeah, we look at the imaging science
• 2:33
  Speaker 2: system of the ISS. We're so used to digital CMOS
• 2:37
  Speaker 2: or CCD sensors in our phones.
• 2:39
  Speaker 1: Today, right, Oh, yes, sensors that capture millions of pixels
• 2:42
  Speaker 1: in a fraction of a millisecond. Right.
• 2:44
  Speaker 2: Voyager had absolutely nothing like that. The system consisted of
• 2:48
  Speaker 2: two cameras. First, you had the narrow angle camera, which
• 2:51
  Speaker 2: was a fifteen hundred milimeter focal length F eight point
• 2:54
  Speaker 2: five katadyoptric castcrain telescope.
• 2:57
  Speaker 1: Okay, hold on Acadia optric cascrein. Let's break that down,
• 3:00
  Speaker 1: because I mean fitting a fifteen hundred millimeter lens on
• 3:03
  Speaker 1: a spacecraft sounds like you're trying to fly a telephone
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  Speaker 1: pole through space.
• 3:06
  Speaker 2: You'd essentially be doing exactly that. If it were a
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  Speaker 2: standard refractive lens, A huge tube sticking out of the
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  Speaker 2: probe would completely throw off its center.
• 3:14
  Speaker 1: Of mass not to mention, making it super vulnerable to.
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  Speaker 2: Vibrations, vibrations, micrometeoroids, you name it. So a cadidioptric castrain
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  Speaker 2: design uses this clever combination of lenses and mirrors to
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  Speaker 2: fold the optical path. Fold it. Yeah, light enters the telescope,
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  Speaker 2: bounces off a primary mirror at the back, travels forward
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  Speaker 2: to a secondary mirror, and then bounces back again through
• 3:36
  Speaker 2: a hole in the primary mirror to reach the sensor.
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  Speaker 1: Ah. So you get the massive magnification, but it's packed
• 3:41
  Speaker 1: into a very short, sturdy barrel.
• 3:43
  Speaker 2: Precisely, and paired with that, they had a wide angle camera,
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  Speaker 2: lower resolution, but much more sensitive to light.
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  Speaker 1: But the true bottleneck, and honestly, the absolute marvel of
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  Speaker 1: the whole system, was the sensor they used to capture
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  Speaker 1: the light, right, the Viticon sensor.
• 3:57
  Speaker 2: Yes, the twenty five millimeter magnetic deflection Vitico sensor.
• 4:00
  Speaker 1: Looking into the details of this thing, it felt like
• 4:02
  Speaker 1: I was reading a manual for a steampunk device. It
• 4:05
  Speaker 1: sounds like early broadcast television tech, not deep space exploration.
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  Speaker 2: Well, because it essentially was adapted from television tech. Right,
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  Speaker 2: Think about how small the active image area on this
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  Speaker 2: target actually was it was just eleven point one four
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  Speaker 2: by eleven point one four millimeters. It's a tiny little square,
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  Speaker 2: a tiny square, And on that square the sensor produced
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  Speaker 2: an image that was eight hundred by eight hundred pixels.
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  Speaker 1: So doing the math there, that means a single pixel
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  Speaker 1: is a mere fourteen microns across, which is microscopic. I
• 4:35
  Speaker 1: mean a human hair is what seventy or eighty microns.
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  Speaker 2: Thick somewhere around there. Yeah, so you have these incredibly
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  Speaker 2: microscopic pixels. But here is the wild part. It wasn't
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  Speaker 2: a digital grid that instantly saved to.
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  Speaker 1: A hard drive, right, no flash memory in nineteen seventy seven.
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  Speaker 2: No, the storage surface of the viticon tube was coated
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  Speaker 2: in the selenium sulfur compound. When the folded light hit
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  Speaker 2: this target, the photons physically changed the electrical chart on
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  Speaker 2: the surface. That's why bright area's got a different charge
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  Speaker 2: than dark areas.
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  Speaker 1: So the image is literally etched in static electricity on
• 5:07
  Speaker 1: this tiny metal plate.
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  Speaker 2: It's an electrostatic latent image. But to get that image
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  Speaker 2: back to Earth, the camera had to read it, and
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  Speaker 2: to do that, an electron beam inside the tube had
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  Speaker 2: to physically sweep across the target line by line by line.
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  Speaker 1: Just detecting the minute differences an electrical charge, and from
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  Speaker 1: what I understand, it took a full forty eight seconds
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  Speaker 1: just to read out a single frame.
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  Speaker 2: Yes, forty eight seconds of continuous mechanical sweeping.
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  Speaker 1: That is agonizingly slow. And the sensor didn't just reset
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  Speaker 1: itself automatically.
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  Speaker 2: Either, Oh far from it. Because the selenium sulfur target
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  Speaker 2: retains a ghost of the previous image a residual charge,
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  Speaker 2: you can just take another photo immediately.
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  Speaker 1: So what did they do?
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  Speaker 2: They had to design a crazy sequence to clear the plate. First,
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  Speaker 2: they hit the sensor with a light flood. They literally
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  Speaker 2: flashed lamps inside the camera to blast the target with
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  Speaker 2: light and equalize the electrical charge.
• 6:00
  Speaker 1: It's like trying to photograph a speeding bullet in a
• 6:02
  Speaker 1: pitch black room using a vintage polaroid. You're just trying
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  Speaker 1: to burn away the previous picture.
• 6:07
  Speaker 2: That's a great analogy. But even the light flood wasn't
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  Speaker 2: enough to make it perfectly uniform. So after the flood,
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  Speaker 2: they had to run fourteen race frames fourteen fourteen. They
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  Speaker 2: fired the electron beam to sweep the target fourteen times
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  Speaker 2: completely wiping it clean and stabilizing it for the next shot.
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  Speaker 2: Only after that entire sequence was the tube ready to
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  Speaker 2: open the shutter again.
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  Speaker 1: Okay, let's put this into context for you listening. You
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  Speaker 1: are flying a one ton spacecraft at roughly thirty five
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  Speaker 1: thousand miles an hour. Right, you are approaching a gas
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  Speaker 1: giant in a near pitch black environment. Because you're hundreds
• 6:39
  Speaker 1: of millions of miles from the sun, and your camera
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  Speaker 1: requires you to take a photo, wait almost a minute
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  Speaker 1: to read it, blast the inside with light, and sweep
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  Speaker 1: the sensor fourteen times before you can take the next picture.
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  Speaker 1: Sounds impossible given the telecom limits and the huge risk
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  Speaker 1: of image smear. How did they manage to capture anything
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  Speaker 1: usable at all? Because of I leave my shutter open
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  Speaker 1: in the dark while moving thirty five thousand miles an hour,
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  Speaker 1: I don't get a planet, I get a blurry streak
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  Speaker 1: of light.
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  Speaker 2: The risk of smear was arguably one of the greatest
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  Speaker 2: engineering hurdles of the entire mission. As Voyager traveled further out,
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  Speaker 2: the ambient sunlight diminished exponentially following the inverse square.
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  Speaker 1: Law, so by the time they reached, say, Neptune, the
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  Speaker 1: sunlight was hundreds of times weaker than here on Earth exactly.
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  Speaker 2: So they needed incredibly long exposure times to gather enough
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  Speaker 2: photons to change the charge on that target. The camera
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  Speaker 2: was originally designed for a maximum exposure of fifteen point
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  Speaker 2: thirty six second seconds.
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  Speaker 1: Which is already a super long exposure for a moving object, right.
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  Speaker 2: But that wasn't nearly enough for the outer planets, so
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  Speaker 2: they had to hack their own system. They started utilizing
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  Speaker 2: those forty eight second readout increments to keep the shutter
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  Speaker 2: open indefinitely. They could leave it open for forty eight seconds,
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  Speaker 2: ninety six seconds, or longer, just soaking in the faint light.
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  Speaker 1: But that brings us back to the smear problem.
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  Speaker 2: It does. To solve the smear, the engineers implemented a
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  Speaker 2: maneuver calls slewing. Rather than having a complex gimbal system
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  Speaker 2: just for the camera, they used the entire spacecraft. Oh wow.
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  Speaker 2: They mathematically calculated the exact relative motion between voyager and
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  Speaker 2: the target planet. Then they fired the spacecraft's microscopic thrusters
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  Speaker 2: to rotate the entire one ton vehicle at the exact
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  Speaker 2: speed required to cancel out the orbital motion.
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  Speaker 1: So they're flying past the planet, but slowly rotating the
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  Speaker 1: whole probe backwards so the camera remains perfectly locked on
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  Speaker 1: a single set of coordinates while the shutter is open.
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  Speaker 2: They essentially turned a deep space probe into an actively
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  Speaker 2: tracking tripod. And keep in mind they were doing this
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  Speaker 2: while transmitting data back to Earth using incredibly weak radio waves,
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  Speaker 2: dealing with light time delays of hours.
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  Speaker 1: It's just brilliant. And the optical processing didn't even end
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  Speaker 1: when the signal reached Earth right because the camera didn't
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  Speaker 1: shoot in made of color.
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  Speaker 2: No, the Viticon sensor only recorded intensity, just light and dark.
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  Speaker 2: To get a color image, the camera featured in a
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  Speaker 2: canical filter wheel containing clear, violet, blue, orange, green, and
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  Speaker 2: UV filters.
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  Speaker 1: Let me guess they had to do that entire painstaking
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  Speaker 1: process for each filter.
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  Speaker 2: Exactly expose, read for forty eight seconds, flood erase fourteen
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  Speaker 2: times through a blue filter, then rotate the wheel, do
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  Speaker 2: it all again through a green filter, then again through
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  Speaker 2: an orange filter.
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  Speaker 1: And then researchers on Earth take those black and white
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  Speaker 1: data sets, assign them color values, and stack them to
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  Speaker 1: create the full color composites we all see in the textbooks.
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  Speaker 2: But even before stacking them, they had to deal with
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  Speaker 2: the physical imperfections of the camera. The cast green telescope
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  Speaker 2: lenses produced barrel distortion.
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  Speaker 1: Which is when the straight lines in the image bow
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  Speaker 1: outward toward the edges right like looking through a fish
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  Speaker 1: eye lens yes.
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  Speaker 2: And the vidicon sensor suffered from intrinsic shading. It didn't
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  Speaker 2: record light uniformly. The corners of the square target might
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  Speaker 2: respond to photons slightly differently than the.
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  Speaker 1: Center, making certain parts artificially darker or brighter. So how
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  Speaker 1: do you even trust the scientific data if the sensor
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  Speaker 1: itself is distorting the light?
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  Speaker 2: Calibration painstaking, obsessive calibration before voyage or ever left Earth,
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  Speaker 2: engineers mapped the exact geometric distortion of the lenses. They
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  Speaker 2: mapped the sensitivity of the target under different light levels
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  Speaker 2: and temperatures. Wow, They created individual calibration files for every
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  Speaker 2: single combination of camera filter and exposure time.
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  Speaker 1: So when a raw image arrived from space, the JPL
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  Speaker 1: computers had to apply these mathematical inversion matrices to digitally
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  Speaker 1: bend the geometry back into shape pixel by pixel before
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  Speaker 1: scientists could even look at it.
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  Speaker 2: It was a symphony of analog engineering and early digital processing,
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  Speaker 2: and I marvel.
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  Speaker 1: At this archaic but brilliant tech, because this very camera
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  Speaker 1: system is what shattered all our assumptions about the outer planets,
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  Speaker 1: starting with our biggest neighbor.
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  Speaker 2: Right Jupiter. Prior to that nineteen seventy nine flyby, planetary
• 10:51
  Speaker 2: science had a very strict, very boring assumption about outer moons.
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  Speaker 2: We looked at our own moons, a dead, heavily cratered rock,
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  Speaker 2: and assumed that was the tees for.
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  Speaker 1: Everything, that small bodies just lose their internal heat very
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  Speaker 1: quickly after they form.
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  Speaker 2: Exactly, so anything orbiting Jupiter or Saturn would just be
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  Speaker 2: a frozen, geologically dead tombstone.
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  Speaker 1: But what they found was the exact opposite. And the
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  Speaker 1: discovery wasn't even made by some senior astronomers staring at
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  Speaker 1: a grand mosaic. It was a navigation engineer named Linda Moribido.
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  Speaker 2: Yes, the Morbida discovery is a perfect example of how
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  Speaker 2: science actually happens. She wasn't looking for geological activity. She
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  Speaker 2: was analyzing an image of Jupiter's moon Io taken by
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  Speaker 2: Voyager one.
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  Speaker 1: She was just doing optical navigation right, boosting the contrast
• 11:34
  Speaker 1: to see the background stars behind the Moon, to pinpoint
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  Speaker 1: voyager's trajectory.
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  Speaker 2: That's right. But when she boosted the contrast, she noticed
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  Speaker 2: something protruding from the dark edge of the Moon. It
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  Speaker 2: was this massive umbrella shaped plume extending hundreds of miles into.
• 11:48
  Speaker 1: Space, active volcanoes. She discovered an active volcano erupting beyond Earth, the.
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  Speaker 2: First time in human history we had ever witnessed active
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  Speaker 2: volcanism on another world, and.
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  Speaker 1: Not just one volcano. Io is considered the most volcanically
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  Speaker 1: active body in the entire Solar System. I love the
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  Speaker 1: nickname it got, the moldy Pizza Moon.
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  Speaker 2: Oh. The nickname is incredibly apt. Because of the constant eruptions.
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  Speaker 2: Io's surface is constantly greenpaving itself with sulfur and sulfur
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  Speaker 2: dioxide frost. Also no impact craters, virtually none, the surface's
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  Speaker 2: too young. Instead, you have these vast modeled patches of
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  Speaker 2: bright yellow, vivid red, black, and green, all driven by
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  Speaker 2: the different temperatures of the sulfur.
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  Speaker 1: So they find a Io and it's exploding, and then
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  Speaker 1: they look at the next moon out Europa, and Europa
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  Speaker 1: doesn'tenough craters either.
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  Speaker 2: Europa presented a totally different kind of shock. Instead of
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  Speaker 2: sulfur volcanoes. Europa was encased in a blindingly bright, perfectly
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  Speaker 2: smooth crust of water ice criss crossed by thousands of
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  Speaker 2: dark fractures.
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  Speaker 1: It looked like a cracked eggshell.
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  Speaker 2: What's fascinating here is that the lack of craters on
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  Speaker 2: Europa meant the exact same thing it meant on Io.
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  Speaker 2: The surface was new, it was actively.
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  Speaker 1: Shifting, revealing that it possesses a fractured ice crust hiding
• 13:00
  Speaker 1: an ocean with more liquid water than all of Earth's
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  Speaker 1: oceans combined.
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  Speaker 2: And this is where we have to look at the
• 13:06
  Speaker 2: underlying mechanics. Yeah, because the immediate question the scientific community
• 13:09
  Speaker 2: faced was thermodynamic, how right?
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  Speaker 1: How can these tiny moons five hundred million miles away
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  Speaker 1: from the sun in freezing temperatures generate enough internal heat
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  Speaker 1: to melt rock on Io and maintain a liquid ocean
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  Speaker 1: on Europa.
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  Speaker 2: The answer they deduce from the voyage data is a
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  Speaker 2: process called tidal heating.
• 13:28
  Speaker 1: Let's really dig into tidal heating, because when most people
• 13:31
  Speaker 1: hear tides, they think of our moon gently pulling on
• 13:34
  Speaker 1: Earth's oceans. Slashing water doesn't melt rock.
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  Speaker 2: No, the tides on Earth are gentle, but the Jupiter
• 13:40
  Speaker 2: system is an entirely different beast. Jupiter's gravity is immense,
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  Speaker 2: and its inner moons, Io, Europa, and Ganymede are lock
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  Speaker 2: on what's called a place resonance.
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  Speaker 1: Meaning their orbits are mathematically.
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  Speaker 2: Linked, precisely linked. For every one orbit Ganymede makes around Jupiter,
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  Speaker 2: Europa makes exactly two and Io makes exactly four.
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  Speaker 1: Oh wow.
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  Speaker 2: Because they keep lining up with each other at the
• 14:00
  Speaker 2: exact same points in their orbits, their gravitational fields constantly
• 14:04
  Speaker 2: tug on each.
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  Speaker 1: Other, and that tugging pulls them out of a perfect
• 14:07
  Speaker 1: circle into elliptical orbits.
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  Speaker 2: That is the critical factor. Because of this resonance, Io
• 14:14
  Speaker 2: and Europa are forced into oval shaped orbits. Sometimes they
• 14:17
  Speaker 2: are closer to Jupiter and sometimes they are farther away.
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  Speaker 1: And that changing distance is the engine of tidal heating.
• 14:23
  Speaker 2: Exactly, gravity follows the inverse square law. It gets much
• 14:27
  Speaker 2: stronger the closer you get. When Io swings in close
• 14:31
  Speaker 2: to Jupiter, the immense gravity pulls harder on the near
• 14:34
  Speaker 2: side of the Moon than the far side, physically stretching
• 14:36
  Speaker 2: the entire solid body of the Moon.
• 14:38
  Speaker 1: Wait, we're not talking about water bulging. We are talking
• 14:40
  Speaker 1: about thousands of miles of solid rock bulging outward.
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  Speaker 2: A tidal bulge of solid rock that can be over
• 14:46
  Speaker 2: three hundred feet high. But then as Io moves further away,
• 14:50
  Speaker 2: the gravitational grip weakens, the rock relaxes and falls back
• 14:54
  Speaker 2: into a more spherical shape, so.
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  Speaker 1: As it orbits, the entire Moon is being rhythmically stretched
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  Speaker 1: and squashed.
• 15:00
  Speaker 2: Imagine taking a thick, solid metal wire like a paper
• 15:03
  Speaker 2: clip and rapidly bending it back and forth in your hands.
• 15:06
  Speaker 1: Yeah, if you touch the hinge point, the metal gets
• 15:08
  Speaker 1: incredibly hot from the internal friction.
• 15:11
  Speaker 2: That friction is tidal heating. The immense gravitational mass of
• 15:14
  Speaker 2: Jupiter is physically needing the interior of Io and Europa.
• 15:19
  Speaker 2: On Io, it's so violent it melts the silicate rock mantle,
• 15:23
  Speaker 2: creating those magma chambers.
• 15:24
  Speaker 1: And on Europo, which is further out, it's not quite
• 15:27
  Speaker 1: violent enough to melt rock to the surface, but it
• 15:30
  Speaker 1: generates enough heat at the core to melt the underside
• 15:32
  Speaker 1: of the.
• 15:33
  Speaker 2: Thick ice shell, thus maintaining a deep, global liquid water
• 15:37
  Speaker 2: ocean in complete darkness.
• 15:39
  Speaker 1: If tidal heating can maintain a warm liquid ocean in
• 15:42
  Speaker 1: the pitch black of space, doesn't that mean our traditional
• 15:46
  Speaker 1: search for Earth like planets in a star's habitable zone
• 15:48
  Speaker 1: is completely too narrow.
• 15:50
  Speaker 2: Voyager fundamentally broke the parameters of astrobiology with this. It
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  Speaker 2: proved habitable environments don't just exist on planets basking in starlight.
• 15:58
  Speaker 2: They can exist in the pitch black subsurface oceans of ice,
• 16:01
  Speaker 2: moons orbiting gas giants.
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  Speaker 1: It's the ultimate lesson in expecting the unexpected, which is
• 16:07
  Speaker 1: a lesson that doubled down when the probes reached the
• 16:09
  Speaker 1: crown jewel of the Solar System's Saturn. Oh.
• 16:12
  Speaker 2: Absolutely, Saturn is entirely defined by its ring system, and
• 16:16
  Speaker 2: when the voyager probes arrived, their cameras zeroed in on
• 16:19
  Speaker 2: the b ring, the broadest, brightest ring. But instead of
• 16:22
  Speaker 2: a uniform disc of ice boulders, they found something completely baffling,
• 16:26
  Speaker 2: the spokes.
• 16:27
  Speaker 1: The mystery of Saturn's spokes.
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  Speaker 2: Yes, the images revealed these dark, radial, small scale features
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  Speaker 2: streaking outward across the bright rings. They looked exactly like
• 16:37
  Speaker 2: the spokes on a bicycle wheel.
• 16:38
  Speaker 1: But the rings aren't solid. They're made of billions of
• 16:41
  Speaker 1: individual chunks of ice and rock. How do you get
• 16:44
  Speaker 1: a cohesive straight line to form across billions of independently
• 16:48
  Speaker 1: moving boulders.
• 16:49
  Speaker 2: That was the paradox the orbital mechanics didn't make sense.
• 16:53
  Speaker 2: The material closer to the planet orbits much faster than
• 16:56
  Speaker 2: the material further away. A straight spoke should instantly get
• 16:59
  Speaker 2: smeared into a spy.
• 17:00
  Speaker 1: So what exactly were they looking at?
• 17:01
  Speaker 2: The voyager data allowed scientists to analyze how light scattered
• 17:05
  Speaker 2: through these features. They deduced the spokes weren't large boulders,
• 17:09
  Speaker 2: they were clouds of submicron sized ice grains.
• 17:12
  Speaker 1: How small is submicron The.
• 17:14
  Speaker 2: Data indicates a mean radius of about point to two microns,
• 17:18
  Speaker 2: that is smaller than the wavelength of visible light. We
• 17:21
  Speaker 2: are talking about microscopic.
• 17:22
  Speaker 1: Dust, and this dust is electrostatically levitated above the ring plane, right, Yes.
• 17:28
  Speaker 2: Like rubbing a balloon on your hair and watching the
• 17:30
  Speaker 2: strand stand up, but on a planetary scale. Yeah. The
• 17:33
  Speaker 2: physics here is a massive environmental tug of war. Saturn
• 17:37
  Speaker 2: has a powerful magnetic field that rotates at a constant speed.
• 17:41
  Speaker 1: While the physical chunks in the ring orbit according to
• 17:43
  Speaker 1: Kepler's laws fast inside slow outside.
• 17:47
  Speaker 2: Exactly when these tiny point to two micron ice grains
• 17:50
  Speaker 2: sit in the ring, they get bombarded by the plasma
• 17:53
  Speaker 2: of Saturn's magnetosphere, which gives them an electrical.
• 17:55
  Speaker 1: Charge, and once charge, the magnetic field grabs them.
• 17:58
  Speaker 2: Voyger observed, they transition between physical states. When they acquire
• 18:01
  Speaker 2: strong charge calculated at a charge to mass ratio of
• 18:05
  Speaker 2: negative sixty coulms per kilogram, electromagnetism overpowers gravity.
• 18:09
  Speaker 1: The magnetic field wins.
• 18:11
  Speaker 2: It rits the grains out of the ring plane, levitates them,
• 18:14
  Speaker 2: and forces them to corretate with the magnetic field ignoring
• 18:17
  Speaker 2: standard orbital speeds. That's why they appear as straight radial spokes.
• 18:21
  Speaker 1: But they don't stay locked forever.
• 18:23
  Speaker 2: No, because they are exposed to solar ultraviolet photo emission.
• 18:27
  Speaker 2: High energy UV photons from the Sun hit the grains
• 18:30
  Speaker 2: and knock electrons off, causing charge to k So.
• 18:33
  Speaker 1: When the charge drops down to what nine of twenty
• 18:35
  Speaker 1: two coulums per kilogram, gravity ticks over again exactly.
• 18:39
  Speaker 2: The grains fall back into the physical ring and transition
• 18:42
  Speaker 2: back to orbiting at the couplearian velocities.
• 18:44
  Speaker 1: Here's where it gets really interesting. This cycle isn't just
• 18:48
  Speaker 1: a neat visual trick, because they are lifted up, moved,
• 18:51
  Speaker 1: and drop back down. They are causing radio mass transport.
• 18:54
  Speaker 1: They are transporting angular momentum within the rings.
• 18:57
  Speaker 2: They are bleeding the energy out of the b ring.
• 19:00
  Speaker 1: I read the transport velocity is negus one times ten
• 19:02
  Speaker 1: to the negative ninth meters per second, and I thought, well,
• 19:05
  Speaker 1: that's fractions of a millimeter. But over millions of years,
• 19:08
  Speaker 1: it acts like a planetary snowplow.
• 19:10
  Speaker 2: It's draining the structural integrity of the rings. The math
• 19:13
  Speaker 2: derived from Voyager implies the b ring will spread and
• 19:16
  Speaker 2: completely dissipate in just six hundred million years.
• 19:19
  Speaker 1: Wait, hold on, if the Solar system is four point
• 19:22
  Speaker 1: six billion years old and the rings will only last
• 19:26
  Speaker 1: six hundred million years, do humanity just happen to evolve
• 19:29
  Speaker 1: at the exact lucky moment to see Saturn with rings?
• 19:33
  Speaker 2: It strongly suggests rings are ephemeral, temporary cosmetic features. It's
• 19:37
  Speaker 2: a profound realization about our place in cosmic time. Voyager
• 19:41
  Speaker 2: proved the Solar system isn't a static machine. It's a dynamic,
• 19:44
  Speaker 2: ongoing process.
• 19:45
  Speaker 1: Wow. If you're finding these insights as mind expanding as
• 19:48
  Speaker 1: I am, take a moment to rate beyond infographics five stars.
• 19:51
  Speaker 1: It really means a lot.
• 19:53
  Speaker 2: Yes, plea too.
• 19:53
  Speaker 1: So after Saturn, Voyager two continued out toward the ice
• 19:56
  Speaker 1: giants Uranus and Neptune, and the mysteries only got Let's
• 20:01
  Speaker 1: talk about geysers in the deep freeze.
• 20:03
  Speaker 2: Voyager two remains the only spacecraft to have ever visited
• 20:06
  Speaker 2: Uranus in Neptune, and when it reached Neptune's largest moon, Triton,
• 20:09
  Speaker 2: it broke all the rules again.
• 20:11
  Speaker 1: Because Triton is nearly three billion miles away, it should
• 20:14
  Speaker 1: be a frozen dead ball of ice.
• 20:16
  Speaker 2: Surface temperatures hover around minus three hundred and ninety degrees fahrenheit.
• 20:20
  Speaker 2: It's also a captured Kuiper Belt object orbiting Neptune backward.
• 20:25
  Speaker 2: But Voyager two revealed a bizarre, highly textured surface called
• 20:29
  Speaker 2: cantalope terrain because.
• 20:30
  Speaker 1: It looks exactly like the wrinkly skin of a.
• 20:32
  Speaker 2: Melon, evidence of massive tectonic deformation. But the truly shocking
• 20:37
  Speaker 2: discovery was active geysers erupting from the surface in a
• 20:40
  Speaker 2: deep freeze.
• 20:41
  Speaker 1: Cry of volcanism ice volcanoes. How do you get geysers
• 20:45
  Speaker 1: at minus three hundred and ninety degrees The rules.
• 20:47
  Speaker 2: Of thermodynamics still apply, but the materials change on Triton,
• 20:51
  Speaker 2: the bedrock is water ice. The magma is likely a
• 20:54
  Speaker 2: slushy mix of liquid water and ammonia heated by tidal forces,
• 20:58
  Speaker 2: but the plumes themselves are driven by nighteitrogen.
• 21:00
  Speaker 1: Right, Triton has a crust of translucent nitrogen ice.
• 21:03
  Speaker 2: Sunlight penetrates the ice, hits darker material underneath, which absorbs
• 21:06
  Speaker 2: the solar energy and heats up. It's a solid state
• 21:09
  Speaker 2: greenhouse effect.
• 21:10
  Speaker 1: The heat gets trapped, warming the nitrogen until it sublemates
• 21:13
  Speaker 1: directly into a pressurized gas, eventually fracturing the ice crust
• 21:16
  Speaker 1: and violently erupting. It proves that even at the very
• 21:19
  Speaker 1: edge of the Solar System, there is enough internal energy
• 21:22
  Speaker 1: to drive geological activity.
• 21:24
  Speaker 2: We saw similar chaotic geology at Uranus on its moon Miranda,
• 21:29
  Speaker 2: which looks like it was shattered to pieces and glued
• 21:31
  Speaker 2: back together.
• 21:32
  Speaker 1: And we can't talk about Voyager without mentioning Titan, Saturn's
• 21:36
  Speaker 1: largest moon, which Voyager one observed. Titan is shrouded in
• 21:39
  Speaker 1: a thick organic haze.
• 21:41
  Speaker 2: It's essentially a planet wide smog factory. The solar UV
• 21:44
  Speaker 2: light and charged particles break apart methane high in the atmosphere,
• 21:48
  Speaker 2: forcing it to recombine into complex organic hydrocarbons.
• 21:52
  Speaker 1: These solid organic particles thalins create that orange haze, and
• 21:56
  Speaker 1: it offers a frozen time capsule glimpse into what early
• 21:59
  Speaker 1: Earth might have looked like before life emerged.
• 22:01
  Speaker 2: The early Earth would have looked like a pale orange dot.
• 22:04
  Speaker 2: Titan is running the experiment of pre life chemistry preserved in.
• 22:08
  Speaker 1: The cold, a pale orange dot that perfectly transitions us
• 22:11
  Speaker 1: to the emotional climax of the mission. Because after Neptune,
• 22:15
  Speaker 1: the primary planetary mission was over, Voyager one was already
• 22:18
  Speaker 1: heading up and out of the ecliptic plane.
• 22:21
  Speaker 2: And before they powered down the cameras forever, Carl Sagan
• 22:24
  Speaker 2: proposed a crazy idea.
• 22:26
  Speaker 1: To turn the camera backward. The date is February fourteenth,
• 22:29
  Speaker 1: nineteen ninety. Voyager one is three point seven billion miles away.
• 22:33
  Speaker 1: That's six billion kilometers or forty point five.
• 22:37
  Speaker 2: Au, staggeringly far. Sagan wanted a family portrait of the
• 22:41
  Speaker 2: Solar System. He wanted to capture the planets as mere points.
• 22:44
  Speaker 1: Of light, and there was massive pushback from engineering. Right
• 22:48
  Speaker 1: pointing the camera near the Sun could destroy the vidicon sensor.
• 22:51
  Speaker 2: Tremendous pushback, but Sagan argued that cultural and philosophical value
• 22:55
  Speaker 2: would be immeasurable. He won. They commanded Voyager one to
• 22:58
  Speaker 2: turn around and take the shot.
• 23:00
  Speaker 1: When Earth appeared as a subpixel speck caught in a
• 23:02
  Speaker 1: band of sunlight, it didn't even fill a single fourteen
• 23:05
  Speaker 1: micron square on that target.
• 23:06
  Speaker 2: Just a tiny bluish white dot.
• 23:08
  Speaker 1: Why does Earth look bluish white from three point seven
• 23:10
  Speaker 1: billion miles away?
• 23:11
  Speaker 2: It's primarily due to Raleigh scattering, the same phenomenon that
• 23:15
  Speaker 2: makes our daytime sky blue. Earth's atmosphere scatters the shorter
• 23:18
  Speaker 2: blue wavelings more efficiently than the red ones.
• 23:21
  Speaker 1: I have to mention the twenty twenty remaster by Kevin
• 23:23
  Speaker 1: MGill Pale Blue Dot Revisited. He used modern software to
• 23:26
  Speaker 1: balance the color channels from the original data while respecting
• 23:29
  Speaker 1: exactly what Voyager saw.
• 23:31
  Speaker 2: If we connect this to the bigger picture, the cultural
• 23:33
  Speaker 2: footprint of this image is massive. Carl Sagan famously wrote,
• 23:37
  Speaker 2: look again at that dot. That's here, that's home, that's us.
• 23:41
  Speaker 1: It's the ultimate perspective shift. It inspired Neil Gaman, storytelling,
• 23:46
  Speaker 1: Jim Bell's book The Interstellar Age, Michael Benson's visual chronicle
• 23:49
  Speaker 1: Far Out.
• 23:50
  Speaker 2: And music Dream Theaters metal track Pale Blue Dot and
• 23:54
  Speaker 2: Melody Sheef's beautiful auto tune track A Glorious Dawn.
• 23:58
  Speaker 1: Looking at the pale Blue Dot is like it's like
• 24:01
  Speaker 1: walking away from your house and turning around when you
• 24:03
  Speaker 1: are a thousand miles away and realizing every triumph and
• 24:07
  Speaker 1: tragedy in your life happened inside a microscopic speck.
• 24:10
  Speaker 2: In the vast cosmic arena. Our squab will seem utterly absurd.
• 24:13
  Speaker 1: So as we look back at Earth, we also have
• 24:15
  Speaker 1: to look at what we set forward. The Voyager Golden
• 24:17
  Speaker 1: Record Humanity's Interstellar Mixtape, curated.
• 24:20
  Speaker 2: By Carl Sagan and Andreian a twelve inch gold plated
• 24:24
  Speaker 2: copper disc attached to both spacecraft.
• 24:26
  Speaker 1: They packed so much onto it. Greetings in fifty five languages,
• 24:29
  Speaker 1: thirty five sounds of earthWhile songs laughter.
• 24:32
  Speaker 2: A heartbeat, one hundred and fifteen images encoded as analog audio.
• 24:35
  Speaker 1: Signals which is brilliant, plus ninety minutes of music Bach Mozart, Blind,
• 24:41
  Speaker 1: Willie Johnson and Chuck Berry, and they included a cartridge,
• 24:45
  Speaker 1: a stylus, and symbolic instructions on how to play it.
• 24:48
  Speaker 2: Using the transition state of a hydrogen atom to define
• 24:50
  Speaker 2: time and pulsars to map Earth's location, and a patch.
• 24:54
  Speaker 1: Of ultra pure uranium two thirty eight as a radioactive clock.
• 24:57
  Speaker 1: But this raises an important question. If extraterrestrials find this,
• 25:01
  Speaker 1: what will they make of Chuck Berry?
• 25:03
  Speaker 2: Right? We have absolutely no idea.
• 25:05
  Speaker 1: More importantly, is the record actually for aliens or is
• 25:08
  Speaker 1: it a symbolic exercise for US forcing humanity to curate
• 25:12
  Speaker 1: the best of what we are?
• 25:14
  Speaker 2: I strongly believe it was an exercise for Earth, an
• 25:16
  Speaker 2: act of cosmic optimism during the Cold War, US building
• 25:19
  Speaker 2: our own idealized tombstone.
• 25:21
  Speaker 1: So what does this all mean for where the probes
• 25:23
  Speaker 1: are right now piercing the plasma bubble? Voyager one is
• 25:26
  Speaker 1: over fifteen billion miles away, Voyager two is over thirteen
• 25:29
  Speaker 1: billion miles away.
• 25:30
  Speaker 2: And they've officially crossed the heliopause into interstellar space Voyager
• 25:34
  Speaker 2: one in August twenty twelve and Voyager two in November
• 25:36
  Speaker 2: twenty eighteen.
• 25:37
  Speaker 1: Let's clarify a massive misconception. Leaving the heliopause the Sun's
• 25:42
  Speaker 1: protective plasma bubble is not the same as leaving the
• 25:45
  Speaker 1: Solar system crucial distinction.
• 25:48
  Speaker 2: Solar system is defined by gravity, non plasma the Sun's
• 25:52
  Speaker 2: gravitational family extends to the outer boundary of the Ort Cloud, and.
• 25:56
  Speaker 1: The timeline is mind bending. It will take Voyager another
• 25:59
  Speaker 1: three hundred years just to reach the inner edge of
• 26:01
  Speaker 1: the Ort.
• 26:01
  Speaker 2: Cloud, and an astonishing thirty thousand years to pass entirely
• 26:05
  Speaker 2: beyond the Solar System's outermost gravitational frontier.
• 26:08
  Speaker 1: Despite a recent computer malfunction on Voyager one, which engineers
• 26:12
  Speaker 1: amazingly fixed by rerouting code fifteen billion miles away, these
• 26:17
  Speaker 1: probes are endlessly wandering. They are interstellar ambassadors.
• 26:21
  Speaker 2: As long as we can pick up their faint radio signals,
• 26:23
  Speaker 2: a piece of human awareness is physically touching the void.
• 26:26
  Speaker 1: Well, thank you so much for joining me to explore this,
• 26:28
  Speaker 1: and to our listeners, thank you for taking this journey
• 26:31
  Speaker 1: with us. If you love this deep dive into the cosmos,
• 26:33
  Speaker 1: please rate beyond infographics five stars.
• 26:36
  Speaker 2: It's been an absolute privilege.
• 26:37
  Speaker 1: We want to leave you with one final lingering realization.
• 26:41
  Speaker 1: Billions of years from now, long after the Sun has
• 26:44
  Speaker 1: expanded into a red giant and swallowed the Earth, destroying
• 26:47
  Speaker 1: every monument, book, and trace of our existence, those two
• 26:50
  Speaker 1: gold plated records will still be intact, silently drifting through
• 26:54
  Speaker 1: the Milky Way Voyager won't just be a record of
• 26:57
  Speaker 1: our solar system. It might ultimately become the singular surviving
• 27:00
  Speaker 1: tombstone of the human race.