While looking at the Moon, have you ever wondered what the finest feature visible to the unaided eye might be? This month is a good time to find out because we have two Full Moons in a calendar month: on the evenings of December 31/January 1 and January 29/30.
Stephen James O’Meara’s Secret Sky: Test your vision: The perigee Moon
January 2010: Take advantage of January's lunar opportunities by locating these naked-eye features.