We know that the earth's axis is tilted 23 ½ degrees. On or about June 21 or 22 each year, the summer solstice occurs for those of us who live in the Northern Hemisphere. On this particular day, the sun's rays are striking earth directly, or at 90 degrees, at a latitude approximately 23 ½ degrees north of the equator. If you were at 23 1/2 degrees north latitude on that day, and you looked up at noon, the sun would be directly overhead.

Imagine you have taken a flight north to New York City. Describe the sun rays at exactly noon on the same day of the year.

A) The sun's rays would also be directly overhead. The sun's rays strike earth at 90 degrees throughout the hemisphere.

B) The sun's rays would also be directly overhead but only for one hour, twelve noon until one o'clock. After that the earth's movement distorts the angle of the sun's rays.

C) The sun's rays will be directly overhead in the Northern Hemisphere during the fall equinox. The movement of earth changes the angle of incidence of the sun's rays throughout the year.

D) The sun's rays will never be directly overhead. The latitude of 23 ½ degrees north is known as the Tropic of Cancer. Above this imaginary line the sun's rays hit earth with decreased angles.