ch29 Flashcards
sphere
a round,three dimensional object
ellipse
an elongated closed curve with two foci
provingnearth is round
objects fall to the center of earth
the earths shadow on the moon
what are two factors that effect gravitational pull
mass and distance
which diameter of earth is longer
the one from the equator
what does the magnetic field protect earth from
harmful solar radiation
which magnetic pole is located in the northern hemisphere
the south magnetic pole
at what degrees is earths axis tilted
11.7 degrees
can magnetic poles flip flop
yes
what is it called when they flip
a magnetic reversal
how often do magnetic reversals occur
200000 years
when did the last magnetic reversal happen
780000
within earths magnetic field what part deflects solar radation
the magnetosphere
what are the scientific names of the norther and southern lights
the aurora borealis and the aurora austrialis
how are the auroras created
charged sun particles colliding with the atmosphere
which month is earth closest to the sun
January
when are we farthest from the sun
in july
time zone
an area 15 degrees wide in which time is the same
rotation
the spinning of earth on an axis
revolution
the motion of earth in an elliptical orbit
ecliptic
a plane of earths orbit around the sun
solstice
occurs when earths rotational axis is tilted directly towards or away from the sun
equinox
earths rotational axis is in a perpendicular line drawn from the from the center of the sun
