astronomy

By Ransom Jones
  • 384 BCE

    aristotle

    He thought the Earth is the center of the Universe and he thought the Universe had invisible shells that planets revolved around.
  • 190 BCE

    Hipparchus

    Was the greatest astronomer of all time and he knew how far the Moon was from the Earth.
  • 100

    Ptolemy

    He found out of the eclipses and modeled the geocentric theory. He relied on Hipparchus’ astronomy work.
  • Period: 1400 to

    Renaissance

    Revival of art, literature, and learning. Scientific method is made.
  • 1473

    Nicolaus Copernicus

    Mathematician and astronomer. He identified the concept of Heliocentric solar system.
  • 1546

    Tycho Brahe

    He is known for his perfectly accurate astronomical and planetary observations.
  • 1564

    Galileo Galilei

    He found Jupiter's moons and he made the telescope. He also made the scientific method.
  • 1570

    Hans Lippershey

    Was a lens maker from Germany but moved to Netherlands. He made the first telescope that was 3x magnification.
  • 1571

    Johannes Kepler

    Tycho Brahe's assistant. He found out that planets revolved in a oval pattern.

  • Giovanni Cassini

    Discovered the division of the rings of Saturn and 4 of Saturn’s moons.

  • Sir Isaac Newton

    Further developed works of Copernicus and Kepler using math, Invented reflecting telescope, and the 3 laws of motion.

  • William Herschel

    Discovered Uranus and its moons, discovered 2 more Saturn's moons, and he believed to have found polar ice on Mars leading to the studies hoping to find water on Mars. He also found that light colors are seen by wavelength.

  • Percival Lowell

    Discovered the planet Pluto and studied the “canals” on Mars. Built the Lowell observatory in Flagstaff, AZ to study Mars.

  • Ejnar Hertzsprung

    One of the inventors of the Hertzsprung_Russell diagram. The HR diagram shows the correlation between the absolute magnitude (brightness) and the spectral type of star.

  • Albert Einstein

    Theory of Relativity (1905) and gravitation.

  • Edwin Hubble

    Using the color of the stars, discovered the universe is expanding. Hubble’s Law, galaxies are moving away from each other. The idea is the basis of the Big Band Theory of how the universe began.

  • Karl Jansky

    Discovered radio waves in the Milky Way.

  • Sputnik

    The Russians sent the first satellite into space.

  • Yuri Gagarin

    First (Soviet) human to orbit the Earth.

  • John Glenn

    1st U.S. citizen to orbit the Earth 3X.

  • The Apollo Program

    Sent humans to the moon and back successfully more than once. It also carried Neil Armstrong, the first man on the moon.

  • Neil Armstrong

    1st person to land on the moon.

  • The First Space Shuttle Flight

    Had the first reusable aircraft and it launched like a rocket, and landed like a plane.

  • Mars Pathfinder Expedition

    This expedition was the first technology on Mars and had Robotic rovers.