Source

Was the demise of the dinosaurs 65 million years ago somehow linked to our Solar System's journey through the galaxy? The way our Sun and its
retinue of planets bounces through the galactic plane may occasionally send comets hurtling to Earth, say researchers.
This is very interesting. We have been lloking to out outer solar system to try and find rogue asteroids and have still only discovered a tiny %
Now if we allow for the fact that the solar system is also travelling possibly towards other asteroid or commet fields the chances of coming across
another huge object (or even a collection of huge objects) is greatly increased.

Astrobiologist William Napier and his team ran simulations of the Solar System's two directions of motion, while also factoring in the Sun's
random encounters with giant molecular star forming clouds. Napier said that passages through these denser parts of the galaxy are responsible for the
Oort cloud disturbances.
This being the case, not only are we constantly in threat of coming across some rogue interstellar object, but out own system (and oort cloud) is
effected as we pass by other large objects.
This got me thinking that not only might we encounter other 'object' but it has been suggested that external cosmc rays have an effects on our
global weather. If we are passing other suns and solar systems that would greatly impact the amount of cosmic debris reaching us. We have all argued
about the solar cycles and our weather patterns in the GW/GC discussions but this is something that never gets a look in but probably should be
considered. Which is something I suggested in
this thread a while back with this
link