ASTRONOMERS

EDWIN HUBBLE

• Lived from 1889-1953
• Had a telescope named after him, called the hubble space telescope.

ISAAC NEWTON

• Lived from 1643-1727
• Greatest scientist in his era
• He discovered gravity

GALILEO GALILEI

• Lived from 1564-1642
• Galileo made major improvements to the
• newly invented telescope.

ARISTOTLE

• Lived from 384- 322 BC
• Aristotle made a model that placed the moon,
• sun, planets, and stars on a series of circles
• that surrounded the earth.
• Believed the earth was round

ARISTARCHUS

• Lived from 312-230 BC
• He attempted to measure the relative
• distance from the moon to the sun.

CLAUDIIS PTOLEMY

• Lived from 87 AD-150 AD
• He developed a geocentric model
• that was used for the next 14
• centuries by astronomers.
• Epicyles

NICOLAUS COPERNICUS

• Lived from 1473- 1543
• Constructed a model of the solar system

JOHANNES KEPLER

• Lived from 1571- 1630
• Formulated three principles, known as kepler's laws.
• 1st law states that planetary orbits are ellipses w/ the sun at one focus.
• 2nd law states that planets move faster in orbits when closer to the sun.
• 3rd law relates the distance of planets from the sun to the time it goes around its orbit.

GEOCENTRIC SOLAR SYSTEM MODEL

• Theory that the earth is in the center of the world.
• Aristotle and Ptolemy used this

HELIOCENTRIC MODEL

• Theory the the sun is in the center of the world.
• Artistarchus, copernicus, kepler, galileo, hubble, and newton.