Is the planet Earth shaped like a sphere?

Answer 1

Planets in he solar sysem are shaped like spheres because The gravity of each planet makes sure that all the mass is equally distributed into a sphere like form.

Objects with no gravity like for example asteroids can appear in random clump shapes

Answer 2

Simple Answer:

The Earth has a spherical shape because of gravity. Each tiny bit of the Earth is attracted to every other bit of the Earth. The force of gravity pulls everything together and the only shape that leaves no part with the possibility of getting any closer to any other part is the shape of a sphere. One can also say that this is the lowest energy configuration.

The Effect of Rotation:

If gravity were the only force involved, then the Earth woud be a perfect sphere, but because the Earth is rotating, there is also a centrifugal force. That force is greatest near the equator, pushing outward, and decreasing the effectiveness of gravity. Thus, the Earth has a bulge of about 0.3% at the equator and technically the shape of the Earth is an oblate spheroid (also called an oblate ellipsoid).

Details:

The Earth's equatorial radius (semi-major axis) is the distance from its center to the equator and equals 6,378.1370 kilometers (3,963.1906 mi).

The Earth's polar radius (semi-minor axis) is the distance from its center to the North and South Poles, and equals 6,356.7523 kilometers (3,949.9028 mi).

The surface of the Earth is obviously not smooth and mountains and trenches represent variations of several kilometers (or miles), about 0.2%. Other relatively minor variations in the shape of the earth are due to variations in the density of the crust and geomorphological processes.

Answer 3

Short Answer:

Earth is an oblate spheroid, slightly bulged at the equator. (0.3%)

Centrifugal force and gravity together are responsible for the shape of the earth.

Explanation:

If the Earth were not rotating, it would only have gravity pulling all of its parts together and that tends to form a perfect sphere. It is not perfect, but the earth takes the shape of an oblate ellipsoid due to centrifugal forces perpendicular to the axis of rotation. The centrifugal force gets larger as the distance from the axis of rotation increases, so it is zero at the poles and increases to a maximum at the equator.

History:

In 1687 Isaac newton published in the Principia a proof that a rotating body with gravitation would develop a surface in the shape of an oblate ellipsoid. (The term oblate spheroid means the same thing.) Half a century later, this became controversial in Europe and in 1736 the King of France sent the mathematician and physicist Pierre Louis Maupertuis on an expedition to Lapland to do the necessary grade measurements.

Data:

The Earth's equatorial radius (semi-major axis) is the distance from its center to the equator and equals 6,378.1370 kilometers (3,963.1906 mi).

The Earth's polar radius (semi-minor axis) is the distance from its center to the North and South Poles, and equals 6,356.7523 kilometers (3,949.9028 mi).

The surface of the Earth is obviously not smooth and mountains and trenches represent variations of several kilometers (or miles), about 0.2%. Other relatively minor variations in the shape of the earth are due to variations in the density of the crust and geomorphological processes.

Answer 4

A sphere approximates the Earth's shape but the actual geometric shape is an oblate ellipsoid due to the combined effects of gravitation and rotation.

The equatorial radius is approximately 22 km greater than its polar radius.

Answer 5

The answer given below by Mr. Michaelalanlee is great! Here goes the further explanation. The shape of the solid sphere will not change with low speed rotation. When the earth formed, it might be in the form of piece of plasma or gas. Which got cooled to liquid eventually. It is the gas or liquid that will take the shape of oblate spheroid, when rotated at low speed. At high speed it will take the shape of disc. The earth became solid, as it cooled down. The same oblate spheroid shape remained there, as the earth became solid in shape.

Answer 6

"Globe" is another word for "sphere." A globe is spherical because that's the definition of "globe."

Answer 7

The pull of gravity over a long time pulls it into a spherical shape.