ASTRONOMERS

ARISTOTLE

• (384-322 BC)
• A shift in a position of an object when viewed from diffrent location is known as parallax
• He discovered the geocentric model were the earth was in the middle

Aristarchus

• He was alive between (310-230BCE)
• He tried to find the distance from the earth to the moon...
• And the earth to the sun
• He came up with the heliocentric model were the sun...
• Was in the middle

Ptolemy

• 100-170CE
• He thought that the planets moved on small circles that moved on bigger circles.
• He thought of the wheels on wheels model
• He observed planets in the sky moving backwards

NICOLAUS COPERNICUS

• 1473 -1543
• He also made a wheels on wheels system but his system fit better
• Heliocentric
• He said that planets made perfect circles around the sun.

JOHANNES KEPLER

• 1571-1630
• He came up with the kepler laws.
• First law states that plnetary orbit are ellipses with the sun at one focus.
• The second law states that planets in there orbit moves faster when..
• They are closer to the sun

GALILEO GALILEI

• 1564-1642
• He observed three other moons
• This showed that earth is not the only thing that can be orbited
• This help support the heliocentric model

ISAACNEWTON

• 1643-1727
• He came up with the newton laws
• If something is not moving it cant move unless pushed by something else

EDWIN HUBBLE

• 1889-1953
• He made the hubble telescope.

GEOCENTRIC

• The geocentric model is were the earth is in the middle of the solar system

HELIOCENTRIC

• It is were the sun is in the middle Of the solar system