Here's a breakdown:
* Ancient Greek Philosophers: While not strictly scientific, philosophers like Pythagoras and Plato proposed a spherical Earth based on philosophical reasoning and observations.
* Eratosthenes: Around 240 BC, Eratosthenes made the first accurate measurement of Earth's circumference, further strengthening the idea of a spherical Earth.
* Aristarchus of Samos: Around 250 BC, Aristarchus proposed a heliocentric model of the solar system, placing the Sun at the center. This model, while later abandoned, implied a slightly elliptical shape for Earth's orbit around the Sun.
* Nicolaus Copernicus: In the 16th century, Copernicus revived the heliocentric model and provided strong evidence for it. His model still assumed circular orbits, but it paved the way for a more accurate understanding of Earth's motion.
* Johannes Kepler: Kepler was the first to definitively propose that planetary orbits, including Earth's, were not circular but elliptical in shape. This was based on his detailed analysis of planetary observations, particularly those of Mars. He formulated his three laws of planetary motion in the early 17th century.
Therefore, Johannes Kepler is considered the first to scientifically propose and prove that the Earth's orbit is elliptical.
