Apart from the fact that both can be abbreviated as MC, I don't see any connection.

I'm more interested in the Galactic Year.

The earth rotates and we have day and night; the earth revolves around the sun and we have seasons. Why shouldn't the galactic year, the time earth takes to make one revolution around the galactic center, approximately 230 million years, have an effect on the solar system and trickle down effects on earth, its biosphere?

Why shouldn't the galactic year, the time earth takes to make one revolution around the galactic center, approximately 230 million years, have an effect on the solar system and trickle down effects on earth, its biosphere — TheMadFool

According to many astrologies, the galactic milk has strong influences on secular matters. Even modern views confirm this.