29 Flashcards
sphere
round, 3 dimensional object, the surface of which is the same distance from the center in all directions
ellipse
an elongated, closed curve with two foci
is earth a perfect sphere
no
what are two things that affect gravitational forces
the masses of each object and the distance between them
which diameter of earth is the longest
equator
what does the magnetic do for earth
protects us from harmful radiation from the sun
which magnetic pull is in the norther hemisphere
south magnetic pole
can these magnetic poles flip
yes
what degrees is earths axis tilted at
11.7
what is the flipping of the north and south magnetic pull called
magnetic reversal
how often do reversals occur
200000 years
last occured 780000 years ago
how often do magnetic reversals occ
what is a magnetosphere
feflects harmful radiaion from the sun
how are the auroras created
electrically charged particles collide with atoms in the atmosphere
what is the scientific name for the nortehrn and soutehrn
boreslis and australis
when is earth closest to the sun
early january
about 147 km
when is earth farthesy from the sun
early july
time zone
an area 15 degrees wide in which the time is the same
rotation
the spinning of earth on its axis, imaginary line drawn from earths north pole to its south pole
revolution
the motion of earth in an elliptical orbit around the sun
eliptic
defined as the plane of earths orbit around the sun
solstice
occurs when Earth’s rotational axis is tilted directly toward the sun or away from the sun
equinox
earths rotational axis is the perpendicular to a line drawn from the center of earth to the center of the sun
tide
rise or fall in the ocean surface
moon phase
reflects the change in appearance of the moon as sen from earth
solar eclipse
occurs when the moon moves directly between the sun and earth and casts a shadow on earth
lunar eclipse
occurs when earth passes between the sun and the moon and casts a shadow on the moon
maria
the dark colored flat lava filled regions on the moons surface
regolith
layer of dusty lunar material produced by collisions between asteroids and comets and the moon
Who devised a method of timekeeping around 3000 B.C.?
Babylonians
What was the symbol for degree taken from?
The Babylonian symbol for the sun
How many degrees does the earth spin in one day?
360 degrees
How many hours does it take the earth to make one full rotation?
24 hours
How many degrees does the earth spin in one hour?
15 degrees
What direction does the sun rise?
East
What direction does the sun set?
West
True or false. All time zones are the exact same size?
False, they are modified to fit around cities, states, and country borders, and other key sites.
How many time zones are there in the world?
24 time zones
Which direction do you move to add hours to the time?
East
Which direction do you move to subtract hours from the time?
West
How many time zones are there in the United States?
6 time zones
What are the names of the time zones?
Mountain time zone Eastern time zone Pacific time zone Alaskan time zone Central time zone Hawaiian time zone
What is a solar day?
The earth’s rotation from the sun in the sky from noon one day to noon the next day
What is a sidereal day?
When a certain star rises above the horizon until that same star rises again
What are the two main reasons for seasons?
The axis tilt and how close earth is to the sun
Which 2 seasons have a solstice?
Summer and Winter
Which month is the summer solstice?
June
Which month is the winter solstice?
December
Which two seasons are equinoxes?
Spring and Fall
Which month is the spring equinox?
March
Which month is the fall equinox?
September
When is the longest day of the year?
During the Summer Solstice
When is the shortest day of the year?
During the Winter Solstice
When are the days almost 12 hours of day and 12 hours of night?
During the spring equinox and during the fall equinox
how many days does it take the moon to revolve around earth
27.3 days
a complete lunar phases cycle takes 29.5 days, what is this called
synodic month
do we ever see the back side of the moon
no
what causes a tide to rise or fall
gravitational pull of the sun and the moon
what is the rise of sea level
high tide
after the sea level rises how many hours does it take for the sea level drop
6 hours
is the sun or moon farther from earth
sun
does the moon or sun cause a greater effect on earths tide
moon
how are the sun, earth, and moon aligned for spring tides
straight line in exact order
how are the sun, earth, and moon aligned for neap tides
90 degree angle
what does the phase of the moon you see depend on
positions of the moon, earth, and the sun relative to one another
when does a new moon occur
when the moon is between the earth and the sun
how many phases of the moon are there
8
what is the definition of waxing phases
the illuminated portion that we see appears larger each night
what is the definition of waning phases
the illuminated portion that we see appears smaller each night
what are the moon phase names
new waning cresent 3rd quarter waning gibbious full waxing gibbious 1st quarter
where is the word month derived from
moon
how are the earth, moon, and sun aligned during a lunar eclipse
earth passes directly between the sun and moon
how are the depressions on the moon formed
by meteoroids, asteroids, and comets
are there mountains on the moon
yes
which side of the moon is thicker
back side
is the mantle of the moon a solid or liquid
solid
what did the clementine spacecraft do
2 things
confirmed the thickness of the crust
mineral content
what did the lunar prospector do
3 things
took photos of the moon surface
confirmed the moon has a small iron rich core
evidence of the presence of water ice
what is the giant impact theory
the moon formed 4.6 billion years ago when a mars sized object collided with earth causing debris thrown into orbit
