Ancient Astronomers

By ethanethan
  • 240 BCE

    Eratosthenes

    Eratosthenes
    Calculated the Earth's size and this was important because it showed that Earth was a sphere.
  • 150

    Claudius Ptolemy

    Claudius Ptolemy
    Known for his Theory of Epicycles which was important because it explained retrograde motion.
  • 1577

    Tycho Brahe

    Tycho Brahe
    Observed the Great Comet and concluded that the comet was farther away than the Moon.

  • Nicolaus Copernicus

    Nicolaus Copernicus
    Proposed that planets orbit around the Sun and this was important because it laid the foundation for understanding the motion of heavenly bodies.

  • Johannes Kepler

    Johannes Kepler
    He defined the Laws of Planetary Motion and this was important because it gave the first connection between planets.

  • Sir Isaac Newton

    Sir Isaac Newton
    Came up with the 3 Laws of Motion which was important because it's the basis of our modern Physics.

  • Albert Einstein

    Albert Einstein
    Came up with the Theory of Relativity which showed that time is not constant and neither are mass and weight.