HISTORY OF ASTRONOMY

ARISTOTLE

• A Greek Philosopher
• Thought Earth was the center of all things
• Made views of the solar system known as the parallax
• In his model, he made the planets and everything in the solar system surround the Earth
• These things moved in a circular motion

ARISTARCHUS

• Was a Greek astronomer and mathmatician
• Proposed a heliocentric model of the solar system that was not accepted at the time
• Attempted to measure distances to the moon and the sun
• His observations were too small but was important at the time
• He contributed a lot to science that we base a lot of our astronomy on today

PTOLEMY

• He wrote a book called Almagest that is based on planets
• He developed a detailed geocentric model that many astronomers used
• He was an astronomer, geographer, and a mathmatician
• He believed that a celestial body traveled at a constant speed in a perfect circle
• In his model, he made his planets move on smaller circles that moved on larger circles

COPERNICUS

• A Polish astronomer
• Felt Ptolemy's model was too complicated
• In his model, the planets rotate around the sun
• He used the "wheels on wheels system" for his model
• His model is seen as the first step in the development of modern models

KEPLER

• German mathematician and astronomer
• Realized that planets didn't move in perfect circular paths
• Found that planets move in ellipses
• Formed what are known today as Kepler's Laws
• These laws consist of three parts

GALILEO GALILEI

• Was a scientist who used the scientific method when answering questions
• Made improvements to the telescope
• Observed the moons that orbit Jupiter: Io, Europa, Callisto, & Ganymede
• Today, these moons are known as the Galilean satellites
• Showed that Earth was not the only object that could be orbited

WORK CITED