The main contribution that Copernicus offered to the intellectual discourse was the idea that all planets revolve around the sun. Copernicus's primary offering was to suggest that the geocentric theory that placed the Earth at the center of the universe was inaccurate. Rather, it is the sun that is the focal point for all planetary rotation and movement. This insight became part of the Copernican Revolution, and clearly indicated a paradigm shift from the "earth first" or Ptolemaic system that was widely accepted prior to Copernicus. Humans were part of a larger planetary and solar system and not the center of it.
The influence of the insight that Copernicus developed was profound. It helped to trigger a shift of thought, a changing paradigm with which to analyze the world and the individual's place within it. Copernicus was widely credited with having a major influence on the scientific revolution, which placed scientific inquiry first before all other presuppositions. Copernicus helped to trigger the belief system that would embrace rational thought and inquiry before belief systems and zealous hope. Observations and scientific data became more widely accepted and understood as a result of Copernicus's contribution to intellectual discourse. It is in this light where his influence was profound and helped to inspire other thinkers to come forth with their own theories that were grounded in observable fact and scientific phenomenon.
Copernicus, a Polish astronomer who rose to prominence in the early 1500s, used empirical evidence drawn from studying the stars and the skies to conclude that the solar system was heliocentric, meaning the planets, including the earth, revolved around the sun. Copernicus understood that by conceiving of the sun as a fixed center and the planets as rotating around it, even if he couldn't explain why they did so (remember, this is well before any Newtonian notion of gravity), he could arrange the planets in logical order in terms of their distance from the sun.
Copernicus published his findings in a work called De Revolutionibus shortly before his death. While the consensus opinion, supported by Biblical language and the evidence of the senses, remained that the sun revolved around the earth, his research laid the groundwork for other scientists, such as Keppler and Galileo, who would continue to use the empirical method of basing conclusions on observation rather than received authority.