Reality of Summer and Winter
Many people believe that the reason for the climate change is because the Earth is closer to the Sun in summer and farther from the sun in winter. In fact, Earth’s orbit around Sun is almost a perfect circle. On average the Earth’s distance from the sun is just a little less than 93 million miles. The Earth is farthest from the Sun in July and is closest to the Sun in January. Earth’s changing distance from the sun has nothing to do with the seasons. When Earth is closest to the sun we are in the middle of winter. The climate changes is all about the tilt of the Earth’s axis.
The seasons are the result of Earth’s axial tilt and the condition that the axis always points in the same direction as Earth orbits the sun.
The seasons are the result of the 23.5 degree tilt of the Earth’s axis from the perpendicular to the Earth’s orbital plane. The Earth’s orbital plane is called the ecliptic. The season are also the result of the Earth’s axis pointing in the same direction. In the summer the axis leans us toward the sun even though we are at a greater than average distance from the sun. We lean back from the sun in the winter months, even though we are actually closer to the sun in distance.
During the summer, the sun’s rays hit the Earth at a steep angle. The light does not spread out as much, thus increasing the amount of energy hitting any given spot. Also, the long daylight hours allow the Earth plenty of time to reach warm temperatures.
During the winter, the sun’s rays hit the Earth at a shallow angle. These rays are more spread out, which minimizes the amount of energy that hits any given spot. Also, the long nights and short days prevent the Earth from warming up. Thus, we have winter!
Now you will be able to define the two basic motions of the Earth which are called rotation and revolution.
Rotation: The spinning of a body on its axis. Rotation equals spinning. The Earth rotates on its axis, or the Earth spins on its axis. Both ideas are correct. It takes the Earth one day to complete one rotation. Rotation is responsible for day and night.
Axis: The imaginary line about which a body spins or rotates. Any object which is rotating must have an axis.
Revolution: The orbiting of one object around another. Orbiting equals revolution. The Earth revolves around the sun, or the Earth orbits the sun. It takes the Earth one year to complete one revolution. Revolution is responsible for determining the period of one year.
Tilt: To lean, incline, slope, or slant
Orbit: The path in space of one object as it goes around another body.
Four Seasons: Spring, Summer, Autumn, and Winter… These seasons start respectively on or about the 21st of March, June, September, and December.
Rotation & Revolution: Rotation is to spinning as revolution is to orbiting.