Copyright © 2011 InteractiveScienceLessons.com handout.

Copyright © 2011 InteractiveScienceLessons.com handout

Copyright © 2011 InteractiveScienceLessons.com

Two factors cause EarthTwo factors cause Earth’’s seasons:s seasons:

1. The _____ of earth1. The _____ of earth’’s axis.s axis.

• It leans _____

• Is the result of a massive _____________ , perhaps

the same one that created the ________

2. The _________________ of earth around the sun2. The _________________ of earth around the sun ..

• Average speed: _________ mph

• It takes earth ____________ days to make the

________________ mile journey

• But it’s always in the same place on the same

day every year

1.blanks-rotation

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1. The _____ of earth1. The _____ of earth’’s axis.s axis.

•It leans _______

•Is the result of a massive _____________ , perhaps

the same one that created the ________

tilt23 ½

collisionmoon

Label degrees

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North Pole

South Pole

set up flashlight

15 N.

30 N.

45 N.

15 S.

30 S.

45 S.

equator

axis

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20 cm

Flashlight is parallel with table

mark red line in north

Lean the northern hemisphere towards flashlight

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15

38

23

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Copyright © 2011 InteractiveScienceLessons.com comparison

NºSº -

Nºx 100 =

44%

15

48

33

23º33º -

23ºx 100 =

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Same light, same distance, but the tilt causes it to be 44% more concentrated in the northern hemisphere.

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2. The _________________ of earth around the sun2. The _________________ of earth around the sun..

•Average speed: _________ mph

•It takes earth ____________ days to make the

________________ mile journey

•But it’s always in the same place on the same day

every year

revolution66,000365.26

600,000,000

diagram-add axis/equator

Copyright © 2011 InteractiveScienceLessons.com Compare axes

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See how earth’s axis stays tilted the same all the way

around the sun?

finish-arrows, label

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summer

winter

summer

winter

2 summary statements

?

?

?

?

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Summary• The tilt of the axis causes the hemisphere leaning towards the sun to receive more concentrated sunlight

•As the earth moves around the sun, the hemisphere leaning towards the sun changes

consequences

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Homework- Consequences. What if…

(stand your earth straight up and move it around your sun)

(keep it tilted, but don’t revolve around the sun)

II. …the earth suddenly stopped revolving around the sun?

I. …the earth’s axis was not tilted?

matching

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Easter

Set clocks ahead one hour

Set clocks back one hour

Harvest moon

Groundhog Day

Blue Moon

Equinox (1st day of spring or fall)

Summer Solstice (longest day)

Winter Solstice (shortest day)

An unusual 5th full moon during a quarter of the year

The first full moon after the autumnal equinox

When the sun is directly over the Tropic of Capricorn

The first Sunday following the 1st full moon on/after vernal equinox

The second Sunday in March

When the sun is directly over the equator

The second Sunday in November

Four days before the cross-quarter (mid-point between winter/spring)

When the sun is directly over the Tropic of Cancer