1633: The Inquisition's trial against Galileo begins. Suspected of heresy for supporting Copernicus's heliocentric model, the Florentine scholar is forced to abjure his discoveries. 

 1817: The comet hunter joins the stars. Charles Messier passes away in Paris, leaving behind the most famous catalogue of the deep sky. This directory of 110 "nebular" objects ranging, from globular clusters to distant galaxies, remains to this day the essential reference map for anyone gazing into the infinite.

Image credits : commons.wikimedia.org