Tychonic model of the cosmos

The Tychonic model, proposed by astronomer Tycho Brahe in the late 16th century, is a geocentric system where Earth remains stationary at the center, with the Sun and Moon orbiting it. However, unlike earlier models, the Sun and Moon orbit Earth, while other planets—Mercury, Venus, Mars, Jupiter, and Saturn—revolve around the Sun. This hybrid model merges elements of the Earth-centered and heliocentric ideas, aiming to align with observed planetary motions. It was a compromise that accounted for the lack of observable stellar parallax and supported geocentrism while incorporating some aspects of heliocentrism.