Planetary, Lunar, and Stellar Visibility presents a 3-color diagram that
shows when a planet, a star, the moon or the sun is visible during any year
from 3000 BC to AD 6000 at any location on the earth. The vertical axis marks
the months of the year, the horizontal axis marks the hours of the day. The
three colors create a contour map effect and show whether the body is under
the horizon (black) and invisible, above the horizon with the sun (light
color) and invisible, above the horizon without the sun (shaded color) and so
possibly visible. (in Education)