"Commentariolus" is a brief astronomical treatise that outlines the heliocentric theory, proposing that the Sun is stationary at the center of the universe and that the Earth, spinning on its axis once daily, revolves around the Sun annually. This revolutionary model challenged the long-held geocentric views of Ptolemy and Aristotle, suggesting instead a universe with planets, including Earth, orbiting in circular paths. The work, not widely circulated during its time, laid foundational ideas that would later be expanded and detailed, significantly altering the course of astronomy and science by challenging the way humans perceived the structure of their universe.