Full Name: Galileo Galilei

Lived Between: 1564-1642

Nationality: Italian

Primary Occupation: Astronomer

Claim to Fame: Galileo determined that the acceleration of falling objects were independent of their weight, and he was also the first to use a new invention called the telescope to study the stars.  He observed sunspots, the moon's surface, Saturn's rings, and the orbit of Jupiter's moons. His discovery that the earth was circling the Sun, and not the center of the Universe itself, challenged Aristotle's idea of the "perfection of the heavens", which had until then been incontrovertible.

Recommended Book: Discoveries and Opinions of Galileo: Including the Starry Messenger (1615) -- Galileo Galilei, Stillman Drake (Translator); Paperback

Recommended Link: http://es.rice.edu/ES/humsoc/Galileo/