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I found this aside on one of the graphics rather surprising: > Sometime in the next 2000 years, the Sun is expected to leave a local cloud of gas and dust. Af

I found this aside on one of the graphics rather surprising: > Sometime in the next 2000 years, the Sun is expected to leave a local cloud of gas and dust. After that, it may enter the G cloud. 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. Mostly surprised that I hadn't heard more about this. 2000 years is practically tomorrow in cosmological time! A little more here: https://en.wikipedia.org/wiki/Local_Interstellar_Cloud https://en.wikipedia.org/wiki/Local_Interstellar_Cloud

stevenjgarner 4y ago
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 https://en.wikipedia.org/wiki/G-Cloud
jorgesborges 4y ago
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.
nuccy 4y ago
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.
Archelaos 4y ago
> > 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.

stevenjgarner 4y ago

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 https://en.wikipedia.org/wiki/G-Cloud

jorgesborges 4y ago

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.

nuccy 4y ago

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.

Archelaos 4y ago

> > 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.