ASTRONOMERS

ARISTOTLE

• Aristotle was a Greek philosopher
• He lived from 384-322 BCE
• He came up with the idea that the earth was in the center of everything

ARISTARCHUS

• He was a Greek astronomer and mathematician
• Lived 310-230 BCE
• Came up with the heliocentric model of the solar system
• He was the first to try to measure how far away the sun was from the moon

PTOLEMY

• He was an astronomer, geographer, and mathematician
• Lived 100-170 CE
• He believed that planets move in circles while circling other things
• New geometric model
• "Wheels on wheels"

COPERNICUS

• He was a polish astronomer
• Lived 1473-1543
• His theory was like Ptolemy but more observent
• His model put the sun in the middle
• He said that the traveling planets made perfect circles

KEPLER

• He was a German mathematician and astronomer
• Lived 1571-1630
• He had three laws known as Kepler's Laws

GEOCENTRIC MODEL

• Aristotle created this model
• Geocentric means "earth centered"
• So this model shows the earth in the center of the planets

HELIOCENTRIC MODEL

• This was first created by Aristarchus
• It was later improved by Copernicus
• It shows the sun, not earth in the middle
• So the planets all revolve around the sun

GALILEO

• He was a scientist
• Lived 1564-1642
• He made extreme improvements to the telescope

NEWTON

• He was a physicist and mathematician
• Lived 1642-1727
• He made the laws of motion and other principles
• These principles improved science greatly

HUBBLE

• He was an astronomer
• Lived 1889-1953
• He was responsible for discovering galaxies beyond milkyway