Thank you for this. While the visualization is useful/interesting, it frustrates me how often similar visuals are used in news stories about space junk. Yes, it's a problem, but using visuals like this without proper explanation misrepresents it terribly.
Yes, and they don't add footnotes. From visualization it looks like crash is inevitable. But yeah, otherwise there would be no visualization.
Think about it: they say 19334 objects are tracked. Imagine that many cars or trucks in the world scattered all across. Then extrude that to couple hundreds of kilometers. Would that feel congested to you? 19334 new cars are being manufactured in less than 2,5 hours...
We do love car analogies. I adore them myself. But you did forget one thing. On the surface, a typical car is averaging something like 35 mph. A low earth orbit satellite around 7.8 kilometers per second.
With orbital junk visualizations, relative size isn't that important. What matters is collision probability. Low polar sun-synchronous orbits where the remote sensing stuff typically lives are super crowded, especially at the poles; in contrast, GSO is a well kept orbit with low relative velocities, and the dead stuff drifts away, so it's really safe.
I always try to explain it thusly: “up there” is “bigger” than “down here” because the radius is greater and there’s three-dimensional separation, and nobody “down here” is worried a few hundred thousand or even several hundred million busses might collide, so why worry about it “up there”?