NASA Discovers A Ring Around The Solar System

You don't retrieve those particles; an admittedly absurd extension of your reasoning would imply that it takes 200 million years to image a quasar, because that's how long it takes to retrieve the photons that form your image.

What we're seeing here is both faint and enormous. Both characteristics make it hard to detect, and it isn't bright enough to capture without a long exposure, plus you can't look at it during the day, and you can't see the side beyond the sun... all characteristics that lead to longer imaging times.

Sure, but I guess my point is that we had only indirect data about the fringe of our solar system before, and now that we have more direct data (i.e. actually sending a satellite out there) we discover something pretty big. The data we have about further away galaxies is even more indirect and the light we get from them is subject to any number of possible phenomena we may not have accounted for. The level of confidence about the conclusions we draw though seems way to high given that its clear there are phenomena we don't know about.

If it's perpendicular to the solar systems trajectory, then it could potentially be an aerodynamics issue not taken into account.

AFAIK the solar system is moving at essentially supersonic speeds through the solar medium, which causes the bowshock, so couldn't this just be an eddy current we've been unable to distinguish either because it's not present in smaller scales, or simply because it's normally small enough to be a statistical anomaly?

The physics of our solar systems action are essentially similar to small body physics, the problem is that they're blown up on scale unimaginable to us. Essentially our comparison of physics is akin to comparing getting up to turn the tv on with a trip to Alpha Centauri and back.