Hi my name is Spencer, have you ever thought or wondered how big or what shape the Earth is?  

As you may not know the Earth is not a perfect sphere (3-D circle) its an oblate spheroid. It's flattened at the poles and bulges at the equator.  The Earth is 7926.21 miles at the equator and 7900.11 miles from pole to pole. 

The earth moves two ways. It spins and it moves around the sun. The spinning of the earth is called rotation. It takes a little over 365 days, or one year, for the earth to make one full revolution around the sun.

This here is the heliocentric model made by Nicolaus Copernicus. In astronomy, heliocentrism is the theory that the Sun is at the center of the Universe and/or the Solar System.

Here is the Model itself.

Nicolaus Copernicus was an astronomer who proposed a heliocentric system, that the planets orbit around the Sun; that Earth is a planet which, besides orbiting the Sun annually, also turns once daily on its own axis; and that very slow changes in the direction of this axis account for the precession of the equinoxes.

Astronomer: a scientist who studies the universe beyond the earth.

An Astronomer that helped contribute to the Heliocentric Theory 

Galileo discovered evidence to support Copernicus' heliocentric theory when he observed four moons in orbit around Jupiter. Over time Galileo deduced that the “stars” were in fact moons in orbit around Jupiter.

He subsequently used his newly invented telescope to discover four of the moons circling Jupiter

Johannes Kepler was a German astronomer, who also improved and helped the heliocentric theory

While Copernicus rightly observed that the planets revolve around the Sun, it was Kepler who correctly defined their orbits. In an attempt to prove his theory, Brahe compiled extensive astronomical records, which Kepler eventually used to prove heliocentrism and to calculate the orbital laws.

Isaac Newton, English physicist and mathematician, who was the culminating figure of the Scientific Revolution of the 17th century. he also contributed to the theory 

This effectively removed the last doubts about the validity of the heliocentric model of the cosmos which argued that the Sun (not the Earth) was at the center of the planetary system. His work also demonstrated that the motion of objects on Earth and of celestial bodies could be described by the same principles.