# How Fast Does the Earth Spin

Do you know how fast does the Earth spin around its own axis and the Sun? Did you know that the speed of earth is slower in some parts and is faster in others?
Rohini Mohan
Have you ever wondered as to how fast does the Earth spin, on its axis and how come we manage to stay rooted to the Earth's surface despite its supreme velocity? Well the gravitational force keeps us rooted while the Earth's extreme momentum, doesn't allow us to feel the Earth's rotation! Finding out the exact speed of the Earth's rotation, from the equator, basically answers most of the other queries. Let's figure out the Earth's speed around its own axis and around the Sun.

When we talk about the Earth's speed, we have to keep in mind that speed is always measured in context to or in comparison to another relative object. Which means that motion can be measured only when there is a reference point. For example, the Earth's speed can be calculated only in context to its own axis, the Milky way, the Solar System, the surrounding celestial objects or the Sun. Therefore, figuring out the speed of the Earth's revolution around the sun will involve using the Astronomical Unit (AU). The Earth takes one year or 365 days to complete one single revolution around the Sun, considering the distance from Earth to Sun. The Earth spans 93 million miles on its orbit to revolve around the Sun, the Earth revolves at 30 km/sec or at 18.5 miles/sec around the Sun.

The Earth spins around its axis every 23 hours 56 minutes and 04.09053 seconds which is approximately to be taken as 24 hours. The axis is an imaginary line that crosses through the center of the Earth from the North pole to the South pole and back. In order to know the speed of the Earth's rotation, we need to find out its velocity at the equator. The way to find that out is to find out the total circumference of the Earth at the equator which happens to be 40,070 Km which is equivalent to 25,040 miles. Now simply divide the:

 Circumference of the Earth/Time taken for one revolution= 25,040 miles/24 hours= 1,038 mph or 1674.66 kph

Therefore 1,038 mph or 1674.66 kph in mph, is the speed of the Earth's rotation, at the equator. Though this speed is based in meters per second, and must not be considered as a constant. This is because, the Earth's speed changes from one location to the other, as it varies with the distance from the equator to either of the poles. The reason being that at the equator the Earth's circumference is far greater and thus has plenty of distance to travel around its axis. On the other hand, as we reach closer to the North pole or the South pole, the distance traveled; reduces drastically.

At the north pole for instance, the Earth's speed plummets to about a mere 1 centimeter-for-every-24 hours! Basically, figuring out how fast does the Earth rotate depends on the latitudinal location of the place, where you may be situated at. Though, the distance traveled by us, decrease as and when we go towards either the North pole or the South pole. For example, the Earth's speed, as calculated from 'Prudhoe Bay', Alaska is only 355 mph!

The places situated in and around the mid-latitudinal zone, have observed that the Earth's spinning speed reduces to a medium range. For instance in places such as New York and Europe, the Earth's speed is approximately about 700 to 900 mph or 1125 to 1450 kph.

Hopefully, now you know, how fast the Earth spins, around the Sun and its own axis. Also, in order to calculate the circumference of the earth from your location, you will need to figure out the 'Cosine' of your latitude and then divide it by 24 (Hours per day).