1.
the circular motion of an object around a central point, or axis, within
2.
the orbital motion of one object around another object
3.
a regular, repeating path that one object in space takes around another one
4.
an invisible line around which an object rotates, or spins
5.
a navigational tool that shows direction using the cardinal directions of north, south, east, and west
6.
how the something is positioned
7.
something you can't see through
8.
a dark shape that appears on a surface when something blocks light from reaching it
