Transcript Motions and Their Effects

Motions and Their Effects
Seasonal Change and Planetary
Movement
Seasons
The
tilt of the Earth’s axis
is 23.5 degrees
This tilt causes seasonal
changes
Winter Solstice
December 21 or 22
North Pole in darkness for
24 hours
South Pole has continual
daylight
Sun is at its lowest point
Why do we have winter?
Fewer
hours of sunlight
during the day
North pole is tilted away
from the sun
Light rays are less direct
Vernal Equinox (equal)
March
20 or 21 (Spring)
Sun is directly over the
equator
Every part of the Earth
experiences equal hours of
day and night
Summer Solstice
June
20 or 21
South Pole in Darkness
North Pole in Light
Sun appears at its highest
point
Why we have summer?
Daylight
hours are longer
Sunlight is more direct
Autumnal Equinox (equal)
September
22 or 23 (Fall)
Equal hours of day and
night
Sun is directly over the
equator
Questions
How
many months apart
are the solstices and the
equinoxes?
How is the vernal equinox
similar to the autumnal
equinox?
Questions
What
are the differences
between the summer and
the winter solstices?
Why do we have changes in
seasons during the year?
Kepler
Each planet moves in an
elliptical orbit (stretched
out circle)
Planets speed up their
orbit as they approach the
Sun and slow down as they
move away from it
Questions
What
was Kepler’s
contribution to the
understanding of planetary
movement?
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