Galileo’s Telescopic Observations of the Moon Among the many mechanical devices Galileo invented was a telescope that could magnify objects thirty times (other contemporary telescopes could magnify objects only three times). Using this telescope, he obtained the empirical evidence that proved the Copernican system. He sketched many illustrations of his observations, including the six phases of the moon shown here.
moon: Biblioteca Nazionale Centrale, Florence, Italy/Eric Vandeville/Gamma Rapho via Getty Images