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
