Answer:
a. He observed that not all heavenly bodies moved around the Earth.
Explanation:
In 1990, the human being placed in space the most accurate eye to look at the universe, the Hubble Space Telescope. But that would not have been possible without a less technological, but equally revolutionary invention: the telescope presented by Galileo Galilei on August 25, 1609. That refractive instrument - 1,27 meters long, with a convex lens in front and another lens ocular concave- allowed the Italian physicist to become the father of modern astronomy.
Thanks to that device, Galileo saw that the Sun, considered until then a symbol of perfection, had spots. The astronomer made direct observations of the star, taking advantage of when the clouds interposed to the solar disk, or in the mornings and sunsets, when the luminous intensity was more bearable, a practice that left him totally blind at the end of his life.
The Moon was not perfect either. Galileo saw what he considered mountains and craters, evidence that the natural satellite, like our planet, was a rocky body and full of irregularities on its surface and not an impeccable sphere made of ether, as it was held back then. These observations questioned the traditional Aristotelian theses on the perfection of the celestial world, which resided in the complete sphericity of the stars.
The Pisa-born astronomer also noticed that Saturn had strange appendages, which he described as similar to two handles. These "appendices" intrigued astronomers for half a century until 1659, when the Dutch mathematician, physicist and astronomer Christiaan Huygens used more powerful telescopes to unravel the mystery about the changing morphology of the second largest planet in the solar system: those handles were actually his rings.
