25 terms

science

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Gravity
The centripetal pulling force that holds the Earth in its orbit around the sun.
Mass
The measure of how much matter is in an object (never changes).
Weight
the heaviness of a person or thing
Rotation
the spin of an object on its axis
revolution
movement of an object in an orbit around another larger object
Orbit
the path that a revolving object takes around another object
Seasons
cause by the tilt of earth on its axis. Because of the angle of the tilt the Earth receives different amounts of daylight hours and concentration of the light energy over each hemisphere
solstice
days with the least and most amount of sunlight (June 21 and Dec 21)
equinox
days when the number of daylight and dark hours are equal (May 21 and Sept 23)
Moon
the only natural orbiting satellite of the Earth
Phase
different shapes of the moon as seen over a period of time 29.5 days; depends on its position around the Earth and the portion of the visible surface seen
Waxing
lighted surface of the moon increases from new moon to full moon
Waning
lighted surface of the moon is decreasing from the right up from full moon to new moon
new moon
the moon is between the sun and earth, completely dark
full moon
we see the entire lighted half of the moon
quarter moon
half the moon is showing
Gibbous moon
when 3/4 of the moon is showing
lunar eclipse
occurs when the earth's shadow fall on the moon; can only occur when moon is in full moon phase
solar eclipse
occurs when the moon passes between the sun and the Earth, and casts a shadow over part of the earth
umbra
shadow directly behind the object. darker part of the shadow. All light is blocked
penumbra
larger shadow behind object. Lighter part of the shadow; partial light blocked
high tide
The side of the earth closest to the moon has its water pulled toward the moon which causes a bulge. High tides always follow the moon
low tide
the area between tidal bulges with low water levels
spring tides
when the sun, moon, and earth are in a line. Tides are higher and lower than normal.
neap tides
sun and moon are at the right angles of the earth. High and low tides are not as high or as low. Can only occur during quarter phases of the moon