Tiny crystals in Earth’s crust may have recorded meteorite and comet impacts as our planet traveled through the spiral arms of the Milky Way over more than 4 billion years, according to new research.

The Sun now lies about 27,200 light-years from the Milky Way’s center — more than one-third of the way into the disk — and roughly 90 light-years above the galaxy’s midplane. During each orbit, which ...