Astronomers

By mlamb92
  • Period: 384 BCE to 322 BCE

    Aristotle

    1. Concluded the Earth is round due to casting a curved shadow on the moon while between the sun and the moon.
  • Period: 310 BCE to 230 BCE

    Aristarchus

    1. First greek to believe in a sun centered universe
  • Period: 276 BCE to 194 BCE

    Eratosthenes

    1. Able to determine the Earth's circumference using trig and the sun.
  • Period: 190 BCE to 120 BCE

    Hipparchus

    1. Identified 850 stars and separated them into six groups based on their brightness.
    2. Measured the length of a year within minutes.
    3. Developed a method to predict the times of a lunar eclipse to within hours.
  • Period: 90 BCE to 168 BCE

    Claudius Ptolemy

    1. Retrograde motion: Mars movement is eastward and then looks like it stops and goes in reverse because the Earth's orbital speed is faster and Earth overtakes it.
  • Period: Dec 31, 1473 to Dec 31, 1543

    Nicolaus Copernicus

    1. Convinced that the Earth is a planet.
  • Period: Dec 31, 1546 to

    Tyco Brahe

    1. Built angle measuring device that helped and used it to measure the location of heavenly bodies.
  • Period: Dec 31, 1564 to

    Galileo Galilei

    1. Four moons of Jupiter
    2. Planets are circular disks.
    3. Venus goes through phases like the moon.
    4. Moon surface is not smooth.
    5. The sun has sunspots or dark regions.
  • Period: Dec 31, 1571 to

    Johannes Kepler

    1. Three Laws of Planetary Movement: A. The path of each planet around the sun is an eclipse B. Each planet travels faster while closer to sun and slower when further away C. P^2=d^3
  • Period: to

    Sir Isaac Newton

    1. First to formulate and test the law of universal gravitation.