Much Better Than Thought: Observing with Galileo’s Telescopes

Abstract

This article examines the telescopic observations made by Galileo Galilei, in a fresh and more thorough way. After reviewing the attribution to Galileo of the instruments of Museo Galileo in Florence, the optical analyses to which they have been subjected, the only direct observations that have been made with them, and the few prior experiments with replicas of these, the paper presents in detail my experiences in replicating all of Galileo’s observations (the most complete set ever made in this field), comparing them with what he reported for each celestial body. This work sheds new light on the nature and methods of the Galilean observations, and on Galileo’s telescopes, proving that they were more powerful, sophisticated, and manoeuvrable than was commonly thought.