Getting into the discussion about who discovered the Earth simply means entering into the subject of who proved that the Earth is not located in the center of the solar system.
During the ancient centuries, the planet Earth was thought to be the center of the universe while other planets, including the moon and Sun, circulate around it.
It was one of the teachings of the church to the people and believing it otherwise would mean being a nonconformist.
The old ancient people thought that the Earth was flat, until the Greeks convince them that the Earth was a sphere.
They thought that everything in the world including the stars were in sphere shapes surrounding the planet Earth.
The thought was natural and instinctive as they did not consider of proving their beliefs.
Any human who stood up and look upon the shy can witness the stars and planets as if they were turning around the Earth.
However the ancient astronomer started studying the world and they discovered few problems.
They did an analysis on the movements of the planets and they appear to move backwards, stop, move forwards and stop again instead of moving straight in the sky.
One of the Greek astronomers, Ptolemy claimed that the planets are in tiny sphere shapes and made circles as they orbited the Earth.
The man who came up with the nature heliocentric model of the universe during the 16th century was Nicolaus Copernicus.
He was the man who discovered the Earth and other plants that circulated the Sun.
He proposed that the Earth and other planets revolved around the sun instead of the planet Earth.
He explained based on his observations upon Galileo's model.
Galileo was the one who observed that Jupiter had its moons and Venus had similar phases as the Earth's moon.
Galileo confirmed Copernicus' discovery later on.
In the 16th century as well, Ferdinand Magellan, a Portuguese who acquired the Spanish citizenship, made an ambitious sea expedition.
He was the man who improved the discovery of Earth.
He showed proofs that the Earth is round by circumnavigating the Earth.
It took a few years for people to accept and get accustomed to the ideas about Earth.
It also took plenty of years for human to prove them right through scientific means.
And finally it had become a proven belief among mankind that the Earth is merely an ordinary planet circulating the Sun.