Every 29.5 days we see a new Moon, or rather we don’t see it, since it’s lost in the glare of the Sun.  But a few days after the new moon, we can see it slowly move away from the Sun and become visible after sunset, with the thinnest crescent growing a bit larger each night.  You may have heard that Mars and Venus also live in the Western sky after sunset, with Venus moving higher and Mars appearing to double back toward the Sun, soon to be lost in the glare of our home star.  Last night I was...