The History of Astronomy

  • 570 BCE


    Pythagoras (570 BC – 495 BC) Believed that Earth was a perfect sphere centered in the celestial sphere also a spherical shell.
  • 384 BCE


    384 BC – 322 BC) planets move different from stars–Geocentric model - Planets and stars revolve around Earth on spherical “shells”; Earth is the center of universe (Ptolemaic system) –geo = Earth; centric = “center”.
  • 190 BCE


    190-120 BC: Considered the greatest astronomer of his time. Wrote the first star and astronomical objects catalog and categorized the brightness or magnitude of stars. First to come precession of equinoxes. He also calculated the distance between Earth and the Moon and Earth’s precessional “wobble” 26,000 years.
  • 100


    100-168(70) AD: Wrote Almagest a set of astronomy manuals which catalogues the stars, eclipses the movement of the sun and moon. His model is the geocentric theory and also called the Ptolemaic Model. He relied on Hipparchus’ astronomy work for the star catalog.
  • 168


    Ptolemy had the idea of a geocentric universe.
  • 500

    Dark Ages/Middle ages

    Dark Ages/Middle ages
    500 AD – 1400 AD Intellectual darkness: the period seems "dark" because of the scarcity of artistic and cultural output,including historical records when compared with both earlier and later times in history.
  • 962

    John Glenn

    John Glenn
    1962– (1921-2016) 1st U.S. Citizen to orbit Earth.
  • 1295

    The Mariner's Astrolabe

    The Mariner's Astrolabe
    This was a circular device used to find ships latitude at sea.
  • 1400


    1400 - 1700 Revival of art, literature, and learning.
  • 1473

    Nicolaus Copernicus

    Nicolaus Copernicus
    (1473 – 1543) Mathematician and astronomer. Identified the concept of the Heliocentric solar system. A system in which the Sun rather than the Earth is the center. Still had fundamental problems with concept though. Helio = “sun”; centric = “center”. Scientific Method of Investigation.
  • 1543

    Heliocentric Universe

    Heliocentric Universe
    Copernicus' Theory
  • 1546

    Tycho Brahe

    Tycho Brahe
    (1546 – 1601) known for his accurate and comprehensive astronomical instruments and planetary observations. –Recorded enough data on the motion of Sun, planets, and moon relative to the fixed stars to within 1 arc minute.
  • 1564

    Galileo Galilei

    Galileo Galilei
    (1564 – 1642) Italian Scientist considered Godfather of modern astronomy.–Turned toy into telescope–Observed/discovered sunspots–Stars not fixed to celestial sphere.–Venus goes through phases similar to the Moon showing that both Earth & Venus orbit the Sun.–4 moons of Jupiter proved that not everything in the sky revolves around the Earth.–His ideas were considered controversial; he was tried and sentenced to house arrest for the rest of his life.
  • 1570

    Hans Lippershey

    Hans Lippershey
    1570-1619: Was a lens maker from Germany but moved to the Netherlands. Believed to be the first to apply for a patent for the telescope design of 3x magnification.
  • 1571

    Johannes Kepler

    Johannes Kepler
    1571-1630 Tycho Brahe’s assistant. Discovered that the orbit of the planets are not circular but elliptical (oval). Unification of astronomy and physics.
  • Giovanni Cassini

    Giovanni Cassini
    1625-1712: Italian who discovered the division of the rings of Saturn. 4 of Saturn’s moons, and the rotation periods of Mars and Jupiter.
  • Sir Isaac Newton

    Sir Isaac Newton
    1643-1724 – Sir Isaac Newton: Further developed works of Copernicus and Kepler using math. Invented reflecting telescope 1668. 3 laws of Motion.
  • William Herschel

    William Herschel
    1738-1822 – William Herschel: Discovered the planet Uranus and its moons. He also discovered 2 more of Saturn’s moons. Believed to have found polar ice on Mars. In 1800, Herschel performed a simple experiment determining the temperature of the different colors of sunlight passed through a prism. He noticed the region just beyond the red color was even higher than light in the visible spectrum, and used his measurements to deduce the presence of what is now known to be infrared radiation.
  • Percival Lowell

    Percival Lowell
    1855 – 1916 Discovered the planet Pluto and studied the “canalis” on Mars. Built the Lowell observatory in Flagstaff, AZ to study Mars.
  • Ejnar Hertzsprung

    Ejnar Hertzsprung
    1873-1967: 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

    Albert Einstein
    1879-1955 – Albert Einstein: Theory of Relativity (1905) and gravitation.
  • Edwin Hubble

    Edwin Hubble
    1889-1953: 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 Bang Theory of how the universe began.
  • Karl Jansky

    Karl Jansky
    1905-1950 – Karl Jansky: Discovered the radio waves are emanating from space. Radio waves are the longest type of energy waves.
  • Sputnik

    1957: Oct 4 1957 The importance of Sputnik to the U.S. In the midst of the Cold War, Russia was successful in launching the first satellite into space to orbit Earth. Putting the Soviet Union ahead of the United States. Science and space travel became a new priority for the U.S. and the educational system. In 1958 President Dwight Eisenhower created NASA (National Aeronautics and Space Admin. The Space Race.
  • Yuri Gagarin

    Yuri Gagarin
    1961: First human (Soviet) to orbit Earth.
  • The Apollo Program

    The Apollo Program
    1963-1972 The Apollo program was designed to land humans on the Moon and bring them safely back to Earth. Six of the missions (Apollos 11, 12, 14, 15, 16, and 17) achieved this goal. Apollos 7 and 9 were Earth orbiting missions to test the Command and Lunar Modules, and did not return lunar data. Apollos 8 and 10 tested various components while orbiting the Moon, and returned photography of the lunar surface. Apollo 13 did not land on the Moon due to a malfunction, but also returned photographs.
  • Neil Armstrong

    Neil Armstrong
    1969 – (1921-2016) He became the first human to walk on the moon.
  • The First Space Shuttle flight

    The First Space Shuttle flight
    This was the first flight of the space shuttle model. This event showed that the new model of spacecraft works. It launched like a rocket and landed like a plane. It was reusable.
  • The Mars Pathfinder

    The Mars Pathfinder
    The Mars Pathfinder lands on Mars and explores the terrain on the red planet.
  • Cassini Orbiter

    Cassini Orbiter
    This was a satellite that orbited the Earth and it was named after the scientist Jean-Domenique Cassini.
  • SpaceX Falcon Heavy

    SpaceX Falcon Heavy
    This is the most powerful rocket in the history of rockets. SpaceX launched it early in 2018.