To glass lenses in a long wooden tube.
Large round pits on the moon.
The different shapes of the moon you see from Earth.
When the moons shadow hits Earth or Earth's shadow hits the moon.
The rise and fall of the oceans water every 12.5 hours or so.
The study of the moon stars and other objects in space.
the imaginary line that passes through the Earth's center and the north and south poles.
The movement of one object around another object.
The motion of an object around an internal axis.
The patch of an object as it revolves around another object in space.
Each of the two days of the year when the noon sun is farther north or south of the equator.
Each of the two days of the year when neither hemisphere is tilted toward or away from the sun.
A surface on the moon which has dark flat areas. Marie mean sea.