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June 21
When Fall officially begins in the North Hemisphere
September 22
December 21
When Spring officially begins in the North Hemisphere
March 21
The Earth rotates around...
its axis!
The Earth revolves around...
the Sun
The direction of the rotation and revoluation of the Earth
counterclockwise
The angle of the Earth's equator relative to its axis
90 degrees
(perpendicular)
Because of the Earth's rotation.
(Being on the east coast of the USA, NYC rotates into the Sun's rays before Seattle, being on the west coast of the USA, does.)
The star toward which the axis of the North Pole points
The North Star
(Polaris)
Why the North Pole gets 24 hours of daylight on June 21?
The North Pole is tilted toward the Sun on June 21, the Summer Solstice. As the Earth spins on its axis, the North Pole never leaves the Sun's rays this day.
March 21 & September 22 (The Equinoxes)
Why the Equator (latitude 0 degrees) is generally hotter than areas further north and south in latitude
The Sun's rays hit the Equator at or nearly at a 90 degree angle all year long.
Areas further north and south in latitude get more angled sun rays and therefore less intense light.
The angle at which the Earth's axis is tilted
23.5 degrees
Why it is summer in Chile when it is winter in Seattle
Because of the Earth's tilt, when the southern axis is tilted toward the sun, Chile gets summer and Seattle gets winter.
(Chile and Seattle are on the South and North hemispheres. When one hemisphere receives intense light, the other hemisphere doesn't. )
The middle of Summer
August 9
The middle of Fall
November 9
The middle of Winter
February 10
The middle of Spring
May 8
The difference between revolving and rotating
Revolving is to go around something, as in an orbit around the sun.
Rotating is to spin around something, as in around an axis.
From January to December, the graph of daylight hours in Seattle looks like...
A valley, a hill, then another valley
From January to December, the graph of the daylight hours in Chile looks like...
a hill, a valley, a hill
opposites (when Seattle has low daylight hours, Chile has high daylight hours and visa versa)
From January to December the graph of the daylight hours at the South Pole looks like...
a flat line at 24 hours, a dot at 12 hours, a flat line at 0 hours, a dot at 12 hours, a flat line at 24 hours
From January to December the graph of daylight hours at the North Pole looks like...
a flat line at 0 hours, a dot at 12 hours, a flat line at 24 hours, a dot at 12 hours, a flat line at 0 hours