Understanding the Truth behind Earth’s Orbit

There was a period when astronomers used to believe that we live in a universe where Earth is at the center of everything. The sun, as per them, rotated around the earth, which caused sunrises and sunsets and a similar vision applied to the movements of the moon and the planets.

But the theory failed to suffice certain questions, including how sometimes a planet would back up in the sky before resuming its forward motion. This motion, known as retrograde motion, occurs when Earth is "catching up" with another planet in its orbit.

Mars, for example, orbits farther from the sun than Earth. When the Earth and Mars move in their respective orbits, we pass by the Red Planet and when we do so, the planet moves backward in the sky. The Mars moves forward again after the Earth has passed by it.

The speed of the Earth’s spin depends on what latitude the planet is located at. According to US space agency NASA, the distance around the largest part of the Earth (called circumference) is roughly 24,898 miles (40,070 kilometers). Explaining the speed, NASA said if you estimate that a day is 24 hours long, you divide the circumference by the length of the day, which produces a speed at the equator of about 1,037 mph (1,670 km/h).

“The probability for Earth to stop its spin is practically zero for the next few billion years, so you can feel safe in knowing you will stay in place. Theoretically, however, if the Earth did stop moving suddenly, there would be an awful effect. The atmosphere would still be moving at the original speed of the Earth's rotation”, said NASA. “This means that everything would be swept off of land, including people, buildings and even trees, topsoil and rocks”.