(1564-1642) was an Italian scientist and mathematician
who made significant contributions to the fields of astronomy
In 1609, Galileo invented a telescope with a magnification
power nearly 10 times greater than that of the primitive
telescopes that existed in 16th century Europe. The
meticulous observations he made with his telescope led to
the discovery of several significant astronomical objects in
our solar system.
In particular, Galileo observed four small bodies orbiting
Jupiter which he correctly identified as moons. He
used this observation as evidence for a heliocentric, or
Copernican theory of the
motions of planets.
The heliocentric theory
placed Earth at the center of the solar system and suggested
that it has many orbiting bodies such as the Moon, the Sun,
and other planets. Galileo reasoned that if Jupiter, like
Earth, had orbiting moons, then Earth might be just another
one of the many planets of the solar system - not the center
of the universe.
This assertion (among others) in his influential book
Dialogue Concerning the Two Chief World Systems,
resulted in a charge of heresy by the Catholic Church.
He was found guilty in 1633 and spent the rest of his life under
In 1992, Pope John Paul II
issued a formal apology for the Galileo trial.