I agree wholeheartedly with all of your sentiments, but I don't think that Kant discovered galaxies or had much interest in them. That honor goes to Messier or Hubble, I believe.
Anyway, from Kant’s Wikipedia:
In the Universal Natural History, Kant laid out the nebular hypothesis, in which he deduced that the Solar System had formed from a large cloud of gas, a nebula. Kant also correctly deduced that the Milky Way was a large disk of stars, which he theorized formed from a much larger spinning gas cloud. He further suggested that other distant "nebulae" might be other galaxies. These postulations opened new horizons for astronomy, for the first time extending it beyond the solar system to galactic and intergalactic realms. From then on, Kant turned increasingly to philosophical issues, although he continued to write on the sciences throughout his life