If there were no moon we would be in continuous sunlight, depending on the tilt which makes for livable seasons, either we would barely see the sun or see several continuous years of sunlight. Our axial tilt is 23 degrees. The moon helps to slow down the rotation of the Earth and slows us down a little more for every day. There would also be no spring or neap tides, these occur when the Sun and moon are on opposite or same side of Earth. Perhaps the biggest role the Moon plays is that it stabilizes the spin axis over long periods of time. The tilt is decreasing and has varied over 22.1 to 23.4 degrees and back over the span on 41,000 years. The moon was closer and appeared larger earlier in history. Annular eclipses are about a third of all solar eclipses with only about a quarter total solar eclipses. In Walking the Path, it is explained that the moon was not only closer but how the distance could be calculated based upon the measurement of a cubit.