5.8 Ancient Astronomers

  • 240 BCE

    Eratosthenes (276 BCE - 194 BCE)

    Eratosthenes (276 BCE - 194 BCE)
    Invented a system of longitude and latitude and made a map of the known world. He discover this in 240 B.C. This discovery is considered important because it helps us locate locations on earth far far away.
  • 127

    Claudius Ptolemy (100 AD - 170 AD)

    Claudius Ptolemy (100 AD - 170 AD)
    He compiled a star catalog and the earliest surviving table of a trigonometric function and established mathematically that an object and its mirror image must make equal angles to a mirror. This is important because without him we basically wouldn't have a map of the world to look at.
  • 1514

    Nicolaus Copernicus (1473 - 1543)

    Nicolaus Copernicus (1473 - 1543)
    He was an astronomer who proposed a heliocentric system, that the planets orbit around the Sun. He made his discovery around 1514. His discovery was considered important because it was the first modern European scientist to propose that Earth and other planets revolve around the sun, or the Heliocentric Theory of the universe.
  • Nov 11, 1572

    Tycho Brahe (1564 - 1601)

    Tycho Brahe (1564 - 1601)
    He showed irregularities in the Moon's orbit and discovered a new star in the Cassiopeia formation. He did this was November 11, 1572. This discovery was considered important because it showed that it was farther away than the Moon and was among the fixed stars, which were regarded as perfect and unchanging.
  • Johannes Kepler (1571 - 1530)

    Johannes Kepler (1571 - 1530)
    Kepler discovered that the orbit of Mars was an ellipse. He discovered this in 1609. This discovery was considered important because it played a key role in the scientific revolution that occurred in the 17th century, contributing a number of scientific breakthroughs including his famous laws of planetary motion.
  • Sir Isaac Newton (1643 - 1727)

    Sir Isaac Newton (1643 - 1727)
    Discovered the laws of gravity and motion and invented calculus. He discovered this in the late 1687s. This discovery was consider important because he basically created physics and showed us how gravity motion worked. Gravity is a major part of our universe.
  • Albert Einstein (1879 - 1955)

    Albert Einstein (1879 - 1955)
    He discovered the photoelectric effect, for which he won the Nobel Prize for Physics in 1921. This discovery was made in 1905. This discovery was consider important because it helped us revolutionized our understanding of the world around us.