chapter 29.1 Flashcards
what is a round, three dimensional object , and the surface of which is the same distance from the center in all directions?
sphere
what is an elongated , closed curve with two foci?
ellipse
is earth a perfect sphere?
No, the equator is longer then pull to pull
what are some the the ancient observatio?
- object fall straight down
- earth’s shadow on the moon
- people see different parts of the worlds see different stars
what are two factors that affect gravitational pull?
masses and distance
which diameter of earth pole to pole or equator , is the greatest?
equator
what does the magnetic field protect the earth from?
harmful radiation
which magnetic pull is located in the northern hemisphere?
South magnetic pole
at what degrees is earth axis at?
11.7 degrees
does the Magnetic pole reverse?
yes
what are the large scale movement call when they reverse?
magnetic reversal
on average when does the magnetic reversals occur
200,000
how long ago did the last magnetic reversal happen?
780.000 years ago
what part of earth’s magnetic field deflects harmful radiation from the sun?
Magnetosphere
what are the two scientific names of the northern and the southern lights?
aurora Borealis
aurora Australis
how are the aurora created?
electrically charged particles collide with atoms in the atmosphere and emit light
what month are we closes to the sun?
january- 147 million km
which month are we farther from the sun
july-152million km
what has an area of 15 degrees wide in which the time is the same?
time zone
what is the spinning of earth on it’s axis called?
Rotation
what is the motion of Earth an elliptical orbit around the sun called ?
Revolution
What is defined as the plane of Earth’s orbit around the sun called?
ecliptic
what is it called when Earth’s rotational axis is tilted directly toward the sun or away from the sun?
Solstice
what is Earth’s rotational axis is perpendicular to a line drawn from the center of Earth to the center of the sun called?
equinox
