FAMOUS ASTROMENERS

ARISTOTLE

• He Thought Earth was the center of everything
• He thought the stars would change positions as the earth moved
• He thought of the idea of the parallax
• Parallax: the apparent shift in the position of an object
• The parallax can not be seen with the naked eye

ARISTARCHUS

• He believed in the heliocentric model of the solar system
• He attempted to measure the relative distance between the moon & sun
• Ratio of his distance he gave was to small
• But it was very important in the use of observation
• Also to solve scientific problems

PTOLEMY

• Believed that a celestial body traveled constant speed in a perfect circle
• He write a book called Almagest
• The book was based on observations of planets
• He devolved a detailed geocentric model
• This model was used buy astronomers for over 14 centuries

COPERNICUS

• Devolved the first detailed heliocentric of the solar system
• He adopted Ptolemy's idea that planetary paths should be in perfect circles
• He also used the "wheels-on-wheels" system

KEPLER

• He had created 3 rules
• He realized that planetary motions to be exactly circular did not meet observations
• Law one: planetary orbits are ellipses with the sun at one focus
• Law two: Planets move faster in their orbits when closer to the sun
• Law three: The distance of a planet from the sun to the time it takes to go around once in orbit

GALILEO

• He started science methods
• He also made significant improvements to the telescope
• He used the telescope to view celestial objects
• He observed moons Io, Europa, Callisto and Ganymede orbiting Jupiter
• His observations showed that Earth was not the only object that could be orbited