What was the main concept of the heliocentric theory?

The main concept of the heliocentric theory is that the sun is at the center of the solar system, and it is this positioning that fundamentally shifts the understanding of our cosmic environment. This theory, most notably proposed by Nicolaus Copernicus in the 16th century, replaced the long-standing geocentric model, which held that the Earth was the center of the universe.

In a heliocentric system, the Earth, along with other planets, orbits the sun. This model accurately explained the retrograde motion of planets and provided a simpler explanation for the observed movements in the night sky. This revolutionary idea laid the groundwork for modern astronomy and enhanced our understanding of planetary motion, celestial mechanics, and the nature of the universe as a whole.

The other options do not capture the essence of the heliocentric theory: the Earth-centered model reflects the outdated geocentric perspective, stating that the Earth is the universe's focal point; asserting that planets revolve around stars refers to a potential extension of the heliocentric view beyond our solar system rather than its fundamental principle; and the idea that the moon affects Earth’s seasons addresses lunar influence without relating to the solar system's structural organization.