Question

In the historiography of early modern astronomy, the standard narrative long held that the adoption of the heliocentric model was a triumph of empirical observation over dogma. However, recent scholarship challenges this neat dichotomy by re-examining the criteria by which sixteenth-century astronomers evaluated competing cosmological models. At the time, the Ptolemaic system, though mathematically cumbersome, offered a degree of predictive accuracy that the early Copernican model struggled to match, largely because Nicolaus Copernicus retained the traditional assumption of perfectly circular orbits. The Copernican model's eventual acceptance was not, as often claimed, immediately predicated on superior predictive power or the resolution of stellar parallax—a phenomenon that would not be demonstrably observed until the nineteenth century.

Instead, the appeal of Copernicanism to its earliest mathematically inclined adherents lay primarily in its conceptual elegance regarding the retrograde motion of planets. In the Ptolemaic system, retrograde motion was accounted for through a complex series of epicycles assigned to each planet without a unified underlying principle. Copernicus’s system, by contrast, naturally derived retrograde motion as an optical illusion resulting from the Earth's own motion around the sun, inherently tying the size of a planet's apparent retrograde loop to its distance from the sun. This structural coherence provided the scaffolding for later astronomers to refine the model into a physically accurate description of the solar system. Notably, however, many observational astronomers of the era remained legitimately skeptical of Copernicanism precisely because its initial iterations required them to abandon established physics—which demanded a stationary Earth to explain why objects fall straight down—without offering a viable replacement physics to govern a moving Earth.

Based on the passage, which of the following can most reasonably be inferred about the sixteenth-century observational astronomers mentioned in the final sentence?