Earth how many km

The mean radius of Earth is at around 3. If you started walking from one end to the other, you would have to cover more than However, things are more complicated than this since Earth is not a perfect sphere.

Earth is a flattened sphere; it has an oblate spheroid shape. The Earth is flattened along its axis from pole to pole resulting in a bulge at the equator.

Depending on where a person traveled from, they would ultimately traverse a different amount of miles — kilometers. Humanity has viewed Earth as spherical since the ancient Greeks. Pythagoras is mostly credited for being the first to suggest this in the 6 th century BCE.

Not much is known about how classical scholars came to this conclusion. Some believe that it all started when the travel and trade between the Greek settlements led to variations in the observable latitude and the change in the area of circumpolar stars.

Specific starts that were visible in Egypt and Cyprus were not visible in northern latitudes, such as Crimea. These variations were noticeable, especially to navigators who often relied on these stars.

Since Eratosthenes did this, the topic became a scientific matter. Later, in the 17 th century, with the advancement of technology, the idea of a perfectly spherical Earth was slowly abandoned.

But Earth and the other rocky planets are much smaller than the gas giants. For example, more than 1, Earths could fit inside Jupiter. Related: What's the speed of Earth around the sun?

Earth's density is 5. Earth is the densest planet in the solar system because of its metallic core and rocky mantle. Jupiter, which is more massive than Earth, is less dense because it is made primarily of gases, such as hydrogen. Earth's mass is 6. Its volume is about billion cubic miles 1 trillion cubic kilometers. The total surface area of Earth is about million square miles million square km.

For comparison, the total surface area of Venus is roughly million square miles million square km , and that of Mars is about 56 million square miles million square km. From his point onwards, the circumference of Earth became a scientific matter.

The idea was first suggested by Sir Isaac Newton , who calculated that the Earth had to be wider at its equator than at the poles. These observations have been confirmed due to the advent of the Space Age and the ability to use orbital satellites to measure the planet from space. The flattened spherical nature of Earth is reflected in terms of its equatorial and meridional circumference. Measured at the equator, the Earth has a circumference of 40, But measured from pole to pole, that is to say, along the meridian line, the Earth has a circumference of 40, If you were to measuring from the center of the Earth out to the equator, you would obtain a radius of 6, But if you were to measure from the center of the Earth to one of the polar regions, you would obtain a radius of 6, And while Earth scientists have meanwhile developed a number of other models that represent the closer approximation of the shape of the Earth, for the most part, it is represented as a sphere.