Class 5: Earth Movements and
What are the changes that happen
• Think about local changes
• Changes elsewhere
• List, with your group, as many seasonal
differences as you can think of
What do you notice about the Sun’s
angle throughout the year?
• Is the sun at the same height each morning
when you wake up?
• Is the sun in the same direction every morning
when you drive to school?
• Does the sun reach the same height in the sky
at its highest throughout the year?
• Think about changes – in your home, along
your commute, at school, etc.
Why is it warmer in Summer?
1 2 3
1. We’re closer to the
Sun in our annual
2. We receive more
3. Our hemisphere is
tilted toward the
sun, making us
closer to the sun
than the other
What causes Earth’s seasons?
• Is it the distance to the Sun?
How does distance to Sun change
• Perihelion – orbital point closest to sun
• Aphelion – orbital point furthest from sun
So what does cause seasons?
• Angle of sun’s rays changes
• This changes the “subsolar point” = point on
Earth that receives Sun’s direct (90 degree)
Where are seasonal changes the most
1 2 3 4
1. Sub Polar
2. Mid Latitudes
3. Sub Tropical
What if Earth were NOT tilted?
1 2 3 4 5 6 7
1. No change
2. Day lengths would stay same all
year long for every latitude
3. All latitudes would experience
the same temp; earth would
have one consistent climate
4. There would be no seasonal
change in weather conditions
5. There would be no diurnal (day
to night) changes in temp
6. Both 2 and 4 would be correct
7. Both 2 and 5 would be correct
What if Earth were more tilted?
1 2 3 4
1. Conditions would stay the same
2. Summers would be warmer and
winter would be colder, but
average temps would be same
3. More direct rays at higher
latitudes in summer would lead
to warmer overall annual temps
4. Less direct rays at higher
latitudes in winter would lead to
colder temps, more snowfall,
more reflection and less
absorption of sun, leading to