Page 161 - Science Course 3 (Book 2)

Mo12-L1a: What Causes Seasons on Earth?

The Sun is 100 times wider than Earth and 10 times The orbit of an object around another object is
wider than the planet Jupiter. The Sun and Jupiter revolution.
are the two largest objects in the solar system.

Motions of the Earth It takes Earth 365.25 days, or one year, to revolve
around the Sun once.
Without the Sun’s pull, Earth would move off into
space in a straight line. An astronomical unit
(AU) can be used to
Earth’s orbit is nearly round, or elliptical. measure distances to
objects in the solar
system.

Earth’s motion without the An AU is the average
Sun’s gravitational pull distance between
Earth and the Sun,
Gravitational approximately
pull of the Sun 150 million km.

Rotation is the spin
of an object around
its axis.

Earth Earth spins, or rotates,
on its axis like a top.

Rotation
(Spin)
152 million km 147 million km 24 hrs
Revolution
(Orbit)
Sun 365.25 days

Earth Orbit

Earth’s rotation causes day and night.

In early July,Earth In early January,
is farther from the Earth is closest
Sun to the Sun
Day Night

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