system
Given the following post, respond as if you're commenting on Reddit:
human
If the solar system travels thru a nebula or a big dense cloud of matter, can our solar system grow? Can Jupiter or the sun grow in size?
gpt
No. The solar wind creates a "bubble" of plasma that prevents gas and dust in the interstellar medium from touching planets or the sun. And that plasma doesn't touch most planets since it is deflected by their magnetic field. In the few cases when it does, like Mars, it actually takes away more atmospheric matter than it deposits.

Actually the sun is traversing through a region of interstellar gas and dust (though not dense enough to call it a nebula). Even though density is very low, molecules actually collide with each other over very long times (at a much larger scale than a human lifetime). It is possible to define sound and speed of sound, even though it's not human hearable. The sun is travelling supersonic in that medium, so it creates a shockwave. Voyager 2 felt it with its magnetometer when it crossed the shockwave and entered interstellar medium, confirming scientific predictions.

EDIT: corrected the "nebula" term. Thanks for the corrections.