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100
Ptolemy
Ptolemy wrote Almagest, a book that gave a detailed theory involving motion of the Sun, Moon, and planets. -
276
Eratosthenes
He was born in 276 B.C.
Hemeasured the distance between two cities and multiplied my 50 and calculated the circumference of the earth to be about 39,000km (24,000miles). -
560
Pythagoras
He moved to Croton in southern Italy and set up a school for philosophical and religious ideas.
He believed that the earth revolved around a massive fire contained deep within its core. -
Feb 19, 1473
Copernicus
Copernicus wrote a paper challenging the geocentric theory. He introduced the idea that the earth and planets revolve around the sun. -
Dec 14, 1546
Brahe
Brahe discovered a nova (a star that becomes very bright then fades in a few months or years) and five comets that were beyond the Moon's orbit. -
Feb 15, 1564
Galileo
Galileo gave proof that the planets circled the sun. -
Dec 27, 1571
Kepler
Kepler was born on Dec. 27, 1571 in Germany. He studied astronomy under Tycho Brahe and supported most of Copernicus's theories.
He developed three laws regarding planetary motion. -
Newton
Newton added the law of Gravitational pull. -
Herschel
Herschel was born in Germany on November 15, 1738. In 1781 Herschel looked beyond the known solar system and made a new discoverr-a new planet! He named it "Georgium Sidus" after England's King George III. -
Hipparchus
He was one of the greatest early astronomers and is known as the Father of Systematic.
known for using mathematics in determining longitude and latitude for positions on earth -
Aristotle
He explained many ideas in studies such as biology, ethics,politics, and astronomy.
He beleved planets moved in a oval-shaped orbits. -
Eudoxus of Cnidus
Eudoxus was the first person to develop the theory that the stars and planets are spheres that move in concentric circles. Concentric means evenly spaced within each other. This explained why the sun and stars move across the sky from east to wast.