Astronomers timeline

By Jasmines04
  • 240 BCE

    Eratosthenes

    Eratosthenes
    He was able to figure out Earth's circumference by using two surface points on the earth. This would allow him to make a map of the known world and give everyone an idea on how big our earth is compared to the sun and other planets. This would help us in the discovery of how much there is on the earth.
  • 150

    Claudius Ptolemy

    Claudius Ptolemy
    His discovery was from the first world view. He believed that the sun, the moon, mercury, and venus all revolved around the earth. He made this discovery, because he was able to see these objects around the earth, so he concluded that they must revolve around the earth. This would be later proved incorrect, but it was a start to what we know now.
  • 1532

    Nicolaus Copernicus

    Nicolaus Copernicus
    He came to the conclusion that every planet, including the Earth, revolved around the sun. He also determined that the earth rotated on its axis. This would change the way that everyone had looked at the world, thinking that the sun revolved around the earth.
  • 1572

    Tycho Brahe

    Tycho Brahe
    He observed the supernova and proved that it was a distant object instead of an atmospheric object. This would disprove Aristotle's 1,800 year old theory. This is important, because he was able to the prove that the universe is not unchanging.

  • Johannes Kepler

    Johannes Kepler
    He discovered that the planets moved in elliptical paths around the sun. This would be his first law. He discovered that the planets will orbit faster the closer they are to the sun. This would be Kepler's second law. This helps us, because it shows us that the planets rotate around the sun at different speeds and some take longer than others to accomplish their orbits.

  • Sir Isaac Newton

    Sir Isaac Newton
    He discovered the laws of gravity. His law states that any object in the universe will pull on each other with only a force proportional to their masses and the distance that is between them. This would help us discover how different planets have moons and why we orbit the sun.

  • Albert Einstein

    Albert Einstein
    He proposed his theory of relativity. This theory proves the theory of gravity. It states that gravity isn't some invisible force that attracts objects together, but rather that it's a curving of space.