Ellipse
elongated, closed curve that describes Earth's yearlong orbit around the Sun
perihelion
The point at which the earth is closest to the sun.
aphelion
The place in the Earth's orbit where Earth is farthest away from the sun.
rotation
the spinning of Earth on its axis
revolution
Earth's yearlong elliptical orbit around the sun
perigee
point of moon's orbit when it is nearest the earth
apogee
when the moon is farthest from earth
new moon
Moon phase that occurs when the Moon is between Earth and the Sun, at which point the Moon cannot be seen because its lighted half is facing the Sun and its dark side faces Earth.
full moon
occurs when all of the Moon's surface facing Earth reflects light
quarter moon
a phase of the moon in which it looks like a half circle
crescent moon
the phase of the moon in which only a curved edge of the moon's side that faced earth is illuminated
gibbous moon
when the size of the illuminated portion of the moon is greater than half but not a full moon
waxing
describes phases that occur after a new moon, as more of the Moon's lighted side becomes visible
waning
(of the moon) pertaining to the period during which the visible surface of the moon decreases
lunar eclipse
the blocking of sunlight to the moon that occurs when Earth is directly between the sun and the moon
solar eclipse
occurs when the Moon passes directly between the Sun and Earth and casts a shadow over part of Earth