Rotation
&
Revolution
http://studyjams.scholastic.com/studyjams/j
ams/science/solar-system/day-on-earth.htm
The study of the moon,
Astronomy stars and other objects
in space.
Axis
The imaginary
line that passes
through the
Earth’s center
and the North
and South poles.
23.5° angle/tilt
Rotation
Earth’s rotation, or spin, on its
axis (23.5)
causes day or night.
Night & Day
• The Earth rotates on it’s
axis every 23hrs and 56
mins (almost 24 hrs)
• The sun shines on only
½ of the Earth at a time.
– ½ of the Earth is
experiencing night time.
While the other ½ is in
daylight!
What Is Rotation?
• For every complete rotation one day
has passed.
Earth spins
counterclockwise.
Sunset from space
Orbit
–Earth’s path as it revolves
around the sun.
–Earth’s orbit is not circular. It
revolves in an oval shape
called elliptical
•Revolution or orbit
– The time it takes for the earth to make
one complete revolution around the
sun is called a year.
One Revolution = 365.25 days
or
One Year
- This is why we have a leap year every 4
years!
Revolution Causes changes of the
seasons?
Seasons are caused by
1. Earth’s revolution around
the Sun
2. the unchanging tilt of the
Earth’s axis.
Common Misunderstandings:
Earth’s changing distance to the Sun
does not cause seasons!
The north pole tilts towards the sun
It is Summer time in countries in the Northern Hemisphere.
It is Winter time in countries in the Southern Hemisphere.
One more time…We
have
seasons because:
1. The tilt of the
Earth’s axis
2. The revolution of
Earth around the
Sun.