Kepler, Galileo and the birth of modern astronomy

The International Year of Astronomy marks the 400th anniversary of Kepler’s Astronomia nova and the first use of the telescope for astronomy, most notably leading to Galileo’s Sidereus nuncius (1610). Kepler’s book for the first time argued strongly for a physical basis to astronomical explanations. Galileo’s work showed that a coherent understanding was more important for scientific progress than specific proofs. The efforts of both astronomers undermined the traditional geocentric cosmology and essentially brought about the birth of modern astronomy.