Modeling the Sky


Seasons video

What causes the seasons on the Earth?

  • The seasons of the Earth are caused by the revolution of the Earth around the Sun on an angular, _______ degree tilt. This causes:
    • The hours of __________ to vary.
    • The intensity of sunlight to change. The ________ the sun gets in the sky, the more concentrated the sunlight.
  • When the Northern Hemisphere is experiencing a season, the _________________ season is occurring in the Southern Hemisphere!


  • When the North Pole is tilted toward the sun, we experience ___________.
  • The sun is directly overhead at the Tropic of ____________, 23.5 degrees N.
  • The sun's rays become more concentrated on the Northern Hemisphere resulting in __________ temperatures.
  • In New Paltz, there are double the hours of ___________ than winter!


  • When the South Pole is tilted toward the _______, we experience winter.
  • The sun is directly overhead at the Tropic of _____________, 23.5 degrees S.
  • The sun's rays become more concentrated on the Southern Hemisphere resulting in __________ temperatures.
  • A day only lasts 8 hours in __________!
  • When we are experiencing winter we are actually closer to the sun by 3 __________ miles!!!


  • At solar noon the sun's rays hit the ___________, 0 degrees latitude, causing everywhere on Earth to have 12 hours of day and 12 hours of night!
  • A side view of the Earth during the equinox looks like this

Review on the Season's and the Sun's Path



The Coriolis effect is what causes winds and ocean currents to bend to the _________ as they move through the Northern hemisphere.

It happens because the Earth rotates at different ____________ at different latitudes.

The Coriolis effect is caused by the ___________ of the Earth.


The Sun's Path

The apparent path of the sun is an arc and it changes with the seasons. Some facts we can observe about the sun's path are:

  • The sun appears to rise in the _______ and set in the ________ .
  • Stars and the moon also appear to rise in the _______ and set in the ________ .
  • Of course, the sun, stars and moon aren't moving, WE are rotating from West to ________!!!
    • How fast are we spinning?
      • Number of degrees in a circle: ________
      • Number of hours in a day: __________
      • Degrees of rotation per hour: ________
  • If you were in space, looking down at the North pole, the Earth spins counterclockwise.

Review of the Rotation of the Earth

Sun's Path in New Paltz

  • The sun is NEVER directly __________ in New Paltz.
  • The highest the sun ever reaches is _____ degrees above the horizon on ____________ solstice.
  • The sun is always due _______ at solar noon (when the sun is highest in the sky).
    • Below the equator, the noon sun is always due North!!

The sun's path changes with your latitude.

  • At what latitude would the sun be overhead at solar noon on March 21? __________
  • When would the sun be directly overhead at 23.5 degrees south? __________
  • In what month is the sun overhead at solar noon at the Tropic of Cancer? ___________
  • What hemisphere of the world would you be in if the noon sun was in the northern sky? ______

Using an instrument called an astrolabe it is easy to find your latitude. The _________________ of Polaris is equal to your _________________ .