Page 171 - Science Course 3 (Book 2)

Mo12-L2b: Why Do the Seasons Change?

Key Concept Mo12–L2b Why Do the Seasons Change?
How Does the Earth Move?
KEY CONCEPTS:
Why is Earth warmer at the equator and colder at 1. Why do the seasons change as Earth moves
the poles? around the Sun?

Vocabulary A-Z

Let us learn some vocabulary

solstice
when earth’s rotation axis is tilted directly toward
or away from the Sun.

Winter Solstice – December 22

equinox
When earth’s rotation axis is tilted neither toward
SUMMARY nor away from the Sun.

How Does the Earth Move?

The gravitational pull of the Sun causes Earth
to revolve around the Sun in a near-circular
orbit.

September Equinox

Let’s Begin

Earth’s rotation axis is tilted and always points
in the same direction in space. Seasons

163