The four divisions of the year (spring, summer, fall and winter) are marked by weather patterns and hours of daylight in a particular region. These patterns are a result of Earth’s 23.5° tilt of axis and its changing position as it orbits the Sun.
To better understand the causes of seasons…
LET’S BREAK IT DOWN!
Earth’s Tilt of Axis
Earth spins around its axis once every 24 hours. The axis is an imaginary line on which Earth rotates. This imaginary line intersects the surface of Earth at the North Pole and South Pole. As Earth orbits around the Sun, it spins on its axis, which is tilted 23.5° relative to the plane of its orbit. Earth’s tilt of the axis points in the same direction in space but changes its position relative to the Sun depending on where it is located during its path of orbit.
During the month of June, the Northern Hemisphere and North Pole point toward the Sun. This causes temperature increases and changes in the atmosphere in the Northern Hemisphere that indicate the season of summer. During the month of December, the Southern hemisphere and South Pole point toward the Sun. This causes temperature increases and changes in the atmosphere in the Southern Hemisphere that indicate the season of summer.
Light is a form of energy that can travel through space. Light energy can be seen by the human eye and is given off by things such as stars, light bulbs, lasers, and hot objects. Light energy is also used by plants to produce food through the process of photosynthesis. When there is more light energy, plants are able to produce more food, which helps them grow.
Light can be measured to determine its intensity or how much energy is hitting a surface. Light travels in a straight line until it hits something else that may block or reflect the light in a different direction. When light travels in a straight line from the Sun to Earth and hits the surface at a 90° angle, it is the most intense and transfers the most energy. This energy is known as solar radiation. When light hits the surface of Earth at a smaller angle, less energy and solar radiation is transferred because the light is spread out over a larger area of Earth’s surface.