A layman’s guide to the motion of the Earth
We’re all just stardust. Literally…— Me.
The motion of the Earth can be a complex concept to wrap your mind around. Why? Because Earth isn’t only moving in one way. Let’s start with the most simple and easy-to-understand of Earth’s motions- rotation. Earth is spinning constantly on its axis. In fact, it is spinning at a speed of approximately 1,000 miles per hour. Pretty fast, huh? This is the origin of day and night. Imagine being a stationary point on a rotating ball with a light source in front of you. At certain points in this rotation, you are directly facing the light source and receiving maximum exposure. As the ball continues to spin, the light source is now at an angle and a little less bright. Continuing on, you will eventually reach a point where you are completely facing away from the light source. You are stationed on the shadow side of the ball. This is night. For Earth, the transition from day, to night, and back to day happens in a period of 24 hours.
Next, the Earth is tilted on its axis. This tilt of 23.5 degrees is the reasons that we have seasons (we’ll get into that more later on). The tilt of Earth’s axis also moves in a circular motion. This, however, takes thousands and thousands of years to form a complete circle so, this motion is fairly irrelevant over the span of a human lifetime.
Finally, the Earth orbits, or rotates, around the sun. This is not done in a perfectly circular shape but is instead, an elliptical with the sun closer to one end. As the Earth reaches the side of the elliptical closer to the Sun, it begins to rotate faster and as it ventures farther from the Sun, its orbit slows. One full orbit around the Sun is considered to be one calendar year or 365 days. Because the Earth is tilted on its axis, on one side of the orbit, the top part of Earth is naturally tilted away from the sun, and on the other side of its solar orbit, the top half of Earth is tilted toward the sun. This tilt has a large effect on the temperatures we feel here on Earth.
All of the above motions are demonstrated in the below picture.