Is there evidence for galactic "seasons"? The Solar Year has huge effects on our climate, and the signs of passing seasons are physically evident on Earth. I recently learned about the Galactic Year. To my understanding, our sun orbits the Milky Way galactic center about every 200-225 million years. Do we know if there are any &quot;seasonal&quot; changes due to our position in the galaxy? One season of the orbital period (50+ million years) feels like a long enough time to leave a mark, if any effect exists:

in the formation of solar system objects?
the bombardment of planets and moons with meteors?
the number, type, distribution, or trajectory of comets?
the shape or density of the Oort Cloud?
in Earth's geologic record?
(at a stretch) mass extinction events?

Obviously you can just say &quot;gravity affects everything, of course the solar system is influenced to some degree by other objects.&quot; But I mean specifically, is there evidence for any cyclical pattern which might be related to our position in the galaxy?
Mass extinctions have been linked with the Solar System's oscillations up and down through the galactic plane (the Galactic Cycle). You could also take a look at this question.