in a typical spiral galaxy, will the orbits of every solar systems be parallel to the galactic plane?

Question

in a typical spiral galaxy, will the orbits of every solar systems be parallel to the galactic plane? In a scenario where beings from one solar systems meet other beings from another system in spacecrafts, is it likely that they meet in virtually the same plane right side up or meet in crazy angles?

Answer 1

Not every one. And not precisely parallel. But most of them, and mostly parallel. So far as we currently suspect.

It has to do with conservation of angular momentum. As the galaxy formed, the stuff in it started to swirl in generally the same direction. That stuff then formed the stars and planets. Swirling in roughly the same direction as the galaxy as a whole.

Barring any odd collisions, that swirling motion would have carried on to this day, with about as much variation between systems as there is within our system. That is, no two solar system objects have exactly the same angle to the ecliptic (either orbital or rotational), but most are close. And there's far more variation in rotational than in orbital angle.

Answer 2

At first, in a solar system the planetary orbits re various as for inclination and eccentricity. However, in our solar system they lie about on the same plane, but they're not parallel to the galactic plane. Our ecliptic has an obliquity of about 60° respect to the galactic plane. The combination of this ecliptic obliquity and the inclination of Earth's axis explains why in a summer night (when we are looking towards the galactic centre) the shape of Milky Way appears to be vertical in the sky from our observational point. If we were parallel to the galactic plane, it should appear nearby parallel to the horizon.