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386-322bce, Aristotle created the GEOCENTRIC model.
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310-230bce, Aristarchus created the HELIOCENTRIC model.
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168bce, Ptolemy created a modifies GEOCENTRIC model of the universe.
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1543, Copernicus used the HELIOCENTRIC model.
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1564-1642, Galileo proved the HELIOCENTRIC model through parallax. He could observe parallax through his telescope. His telescope allowed him to veiw the outer planets.
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Alive during the time of Galileo, Kepler modified the HELIOCENTRIC model to include eliptical orbits.
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On October 4, 1957, the Soviet Union sucessfully launched it nto orbit. It became the first artificial satellite.
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Neil Armstrong and Buzz Arnold were the first people to set foot on another celestial body. There have been 6 total US manned missions to the moon.
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On April 12, 1981, the first spacecraft was launched into orbit using rockets. This was also the first orbital mission.
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NASA's Mars Exploration Rover Mission (MER) is a robotic space mission involving Spirit and Opportunity, two rovers, exploring Mars.
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Alive 1656-1742 Halley and 1642-1746 Newton, the pair tracked Halley's Comet, accurately predicting it's path, proving objects have elliptical orbits.