Ancient Astronomers

By enrehm
  • 240 BCE


    Eratosthenes, in 240 B.C.E, created a set of longitude and latitudes in order to measure the circumference of the Earth. He was only a couple hundred miles off.
  • Period: 100 to 170


    In the 2nd century, Ptolemy mapped out the solar system, showing the the Earth was at the center, and everything was orbiting it. Despite this being flat out incorrect, it led to and influenced much of the ancient thoughts on the Solar System. His theory held up for over 1,000 years.
  • 1514

    Nicolaus Copernicus

    In 1514, Copernicus wrote a theory about the Sun and Earth that challenged all other previous theories. He theorized that the Sun was the center of the Universe rather than the Earth. Now his theory wasn’t without some flaws, but this was the beginning of the modern knowledge of the Solar System.
  • 1572

    Tycho Brahe

    In 1572, Brahe discovered a supernova that had not been present before. This “new star” showed that the universe is constantly changing and is not fixed.
  • Johannes Kepler

    In 1609, Kepler used previous studies of Brahe to figure out that the orbits of the plansts are ellipses, not circles. While doing so, he created his 3 laws, which help us understand our orbit better.
  • Isaac Newton

    In 1665, Sir Isaac Newton discovered that motion is dictated by gravity. This has greatly helped the study of astronomy and physics, and directly allowed Einstein to discover and create his Theory of Relativity.
  • Albert Einstein

    In 1905, Einstein theorized that the speed of light is constant throughout the entire universe. This was important for the understanding of spacetime, which is affected by the intense gravity in space, and allowed modern scientists to understand how gravity and time work better in the universe.