29.1-2 Flashcards
sphere
A round, 3 dimensional object, the surface of which is the same distance from the center in all directions
elipse
an elongated, closed curve with two foci
is the earth a perfect sphere
no, its wider than it is tall
what are two factors that affect gravitational strengh
the mass and distance between an object
is the pole to pole diameter or the equator longer
equator
what does the magnetic field protect earth from
solar flares
the south magnetic pole is located in which hemisphere
northern hemisphere
what degree is earths axis tilted at
11.7
does the earths magnetic poles flip
yes
what is a large scale reversals called
magnetic reversals
how often do magnetic reversals happen
200000 years
when was the last magnetic reversal
780,000
what part of the magnetic field reflects harmful radiation
the magnetosphere
what are the northern and southern lights called
north, aurora borealis
south, aurora australis
how are the auroras created
electrically charged particles collide with atoms
in which month is earth closest to the sun
january
147 million km away
which month are we farthest from the sun
july
152 million kilometers
an area 15 degrees wide
time zone
spinning of earth on its axis
rotation
motion of earth in an elliptical orbit
revolution
the plane of earths orbit around the sun
ecliptic
earths rotational axis is tilted directly toward the sun or away from the sun
solstice
earths rotational axis is perpendicular to a line drawn from the center of earth to the sun
equinox
who devised a method of timekeeping around 3000 B.C.
the babolonians
what was the symbol for degrees taken from
the babalonians symbol for sun
How many degrees does the earth spin in one day
360
how many hours does it take the earth to make one full rotation
24
how many degrees does the earth spin in one hour
15
what direction does the sun rise
east
what direction does the sun set
west
true or false, all time zone are the exact same size
false, they are modified for city’s, states, and country borders
how many time zones are there
24
which direction do you move to add more hours to the time
east
which direction do you move to subtract hours from the time
west
how many time zones are in the us
6
what are the names of the US time zones
central, mountain, eastern, pacific daylight, Alaska daylight, Hawaii,
what is a solar day
sun moves from noon to noon
what is a siderealm day
we look at a specific star and make a rotation to see it again
what are the main two reasons for seasons
which 2 seasons have a solstice
which month is summer solstice
what month is winter solstice
which two season are equinoxes
which month is spring equinox
which month is cfall equinox
when is the longest day of the year
when is the shortest day of the year
when are the days almost 12 hours of daylight and 12 hours of night
winter and summer months
