Unit 3
The Earth – Moon – Sun
System
Vocabulary
Review
the periodic rise and fall of
the water levels in the oceans
and other large bodies of
water
tide
the time required for Earth to
rotate once on its axis
day
a tide of increased range that
occurs two times a month, at the
new and full moons
spring tide
the time required for Earth to
orbit once around the sun
year
the point at which the sun is as far
north or as far south of the equator
as possible; the area of sunlight is
at maximum in one hemisphere and
at minimum in the other
solstice
the outer part of a shadow such
as the shadow cast by the Earth
or moon in sunlight is only
partially blocked
penumbra
the force of attraction between
two objects that is due to their
masses
gravity
the motion of a body that
travels around another body in
space; one complete trip along
an orbit
revolution
a natural or artificial body that
revolves around a celestial body
that is greater in mass
satellite
a tide of minimum range that
occurs during the first and third
quarters of the moon
neap tide
the moment when the sun appears
to cross the celestial equator;
sunlight shines equally on the
northern and southern
hemispheres
equinox
the difference in levels of
ocean water at high and low
tides
tidal range
an event in which the shadow of
one celestial body falls on
another
eclipse
the different appearances of the of
the moon from Earth throughout
the month
lunar phase
a division of the year that is
characterized b recurring weather
conditions and determined by both
Earth’s tilt relative to the sun Earth’s
position in its orbit around the sun
season
a shadow that blocks sunlight;
such as the conical section in
the shadow of Earth or the moon
umbra
the spin of a body on its axis
rotation