High Quality Content by WIKIPEDIA articles! The history of Mars observation dates back to the era of the ancient Egyptian astronomers. Detailed records regarding the position of the planet Mars were made by Babylonian astronomers who developed arithmetic techniques to predict the future position of the planet. The ancient Greek philosophers and Hellenistic astronomers developed a detailed geocentric model to explain the planet`s motions. Indian and Islamic astronomers estimated the size of Mars and its distance from Earth. In the 16th century, Nicholas Copernicus proposed a heliocentric model for the Solar System with the planets following circular orbits about the Sun. This was revised by Johannes Kepler, yielding an elliptic orbit for Mars that more accurately fitted the observational data.