Why do we have seasons?
 Are the Seasons caused by the Earth being closer to or farther
away from the sun?
NO
Closer to the sun in
January, and farther
away in July.
 Perihelion
is the point
along
Earth’s orbit
when Earth
is closest to
the Sun.
 January
 Aphelion is
the point
along Earth’s
orbit when
Earth is
farthest
from the
Sun.
 July
Distance A
Distance B
 Distance B (the tilt)
is so small that it
really does not make
us any closer to the
sun.

Why do we have seasons?
Seasons are caused by different amounts of
sunlight reaching earth because of a
combination of
1. The tilt of Earth and
2. It’s revolution around the sun

Sun’s Path Across Sky

Sun’s Path Across Sky

Flashlight Activity

Flashlight Activity

NO – The amount of energy leaving the flashlight is the same at all times.
Likewise, the average amount of energy leaving the Earth receives is the same.
The energy is more concentrated in “A” because the energy is in a smaller area, therefor the
temperature would be warmer. In B, the energy is spread out over a larger surface,
decreasing the concentration and temperature.
In summer, the light hits us more direct, like in part
“A”, the concentration is greater, we get a lot of heat
therefore temperatures are warmer on average.
In winter, the light hits us indirectly, like in part “B”,
the light is less concentrated and spread out, we get a
little bit of heat therefore temperatures are cooler on
average.