Whoa.

I’m assuming our solar system has moved through various interstellar mediums throughout history, and from reading above it sounds non-trivial. Is it? Do we know anything about how this may have influenced the development of Earth?

Learning this gives me a very “oh my god we’re hurtling through space!” feeing that I haven’t felt in a long time.

> > If it is denser, it would squash the protective magnetic bubble of the heliosphere, potentially exposing the Solar System to a barrage of cosmic rays.

That seems highly exaggerated. The Wikipedia article you mentioned is more sober:

> The Local Interstellar Cloud's potential effects on Earth are greatly diminished by the solar wind and the Sun's magnetic field.

A change in the density of the near interstellar medium would shift the heliopause, but it would require a massive increase in density to move it from where the Voyager probes are now to somewhere close to the inner solar system where it could have a noticeable impact.

Due to stochastic nature of interstellar magnetic fields, cosmic rays, trajectory of which are bent by those, are practically observed from all directions, so even if solar system distorts its own magnetic field this will have almost no effect on vosmic rays flux. Magnetic field is not a shield, for the charged particles it is rather a lens which converges or diverges their trajectories.

Thanks for bringing this to our attention. "The G-Cloud contains the stars Alpha Centauri (a triple star system that includes Proxima Centauri) and Altair (and possibly others)" [0]

[0] https://en.wikipedia.org/wiki/G-Cloud