The month opens with Venus outshining everything else in the predawn sky. The moon glides steadily eastward to keep a rendezvous with Saturn on Oct. 5. This year, though, it’s essentially a tie with September’s full moon, which was almost as close to the equinox. Moon fans will notice its large size, which is best appreciated when the moon is close to the horizon. And don’t miss it in the predawn sky on Oct. 19, when a thin old crescent moon visits Venus.