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Mar 25, 1085
Claudius Ptolemy
Ptolemy was also a mathematician, geographer, and astrologer. He lived in Egypt.Universe. His work enabled astronomers to make accurate predictions of planetary positions and solar and lunar eclipses, -
Feb 19, 1473
NICOLAUS COPERNICUS
In the middle of the 16th century a Catholic, Polish astronomer, Nicolaus Copernicus, synthesized observational data to formulate a comprehensive, Sun-centered cosmology, launching modern astronomy and setting off a scientific revolution. -
Feb 15, 1546
GALILEO GALILEI
Soon after his arrival in Florence in September 1610, Galileo began his observations of Venus. Over time he discovered that the Moon-like phases of Venus demonstrated that the neighboring planet had an orbit independent of Earth. -
Dec 14, 1546
TYCHO BRAHE
Tycho Brahe was the last great naked-eye astronomer. His legacy is a star chart of considerable accuracy and proof that the heavens were not fixed. -
ISAAC NEWTON
Sir Isaac Newton developed the three basic laws of motion and the theory of universal gravity, which together laid the foundation for our current understanding of physics and the Universe. -
HENRIETTA LEAVITT
Discovered the difference between the intrinsic brightness of a variable star and the time it took to vary in brightness, making it possible for others to estimate the distance of these faraway stars, conclude that additional galaxies exist, and begin mapping the Universe. -
Edwin Hubble
Helps design the Hale Telescope on Mount Palomar in California.In 1923 he spotted a Cepheid variable star in what was known as the Andromeda Nebula.