Who theorized that the moon was actually a land form and not a god or a fireball

Galileo Galilei, an Italian astronomer, philosopher, engineer, mathematician and physicist, closely related to the scientific revolution. He made several important contributions to science. In the first place, applying his method of study, he rejected the ideas of Artistoteles (although at the time, he was the scientist with the greatest impact on society) in his theory of the sublunary world (the Earth and everything comprised between the planet and the Moon, an imperfect and changing world) and traslunar (the Moon and beyond, a space with perfect geometric shapes and regular movements). Also, thanks to the telescope, he was able to observe the mountains and valleys of the moon, so he could demonstrate that the lunar surface was not flat, as the Aristotelians claimed.