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Astronomical History

  • Feb 19, 1473

    Nicholaus Copernicus

    Nicholaus Copernicus
    Nicolaus Copernicus was a Polish man who lived during the Renaissance. He was an astronomer and mathematician who created the heliocentric theory, which stated that the planets in our solar system rotated around the sun.
  • Feb 15, 1564

    Galileo Galilei

    Galileo Galilei
    Galileo was an Italian astronomer who was one of the leaders of the Scientific Revolution. His contributions to observational astronomy include the telescopic confirmation of the phases of Venus, the discovery of the four largest satellites of Jupiter (named the Galilean moons in his honour), and the observation and analysis of sunspots.
  • Dec 27, 1571

    Johannes Kepler

    Johannes Kepler
    Johannes Kepler was a German Astronomer who lived during the time of Galileo. Kepler elaborated on Galileo's telescope and made a refracting telescope. Kepler also made the laws of planetary motion. These stated that, "The orbit of every planet is an ellipse with the Sun at one of the two foci" and "A line joining a planet and the Sun sweeps out equal areas during equal intervals of time."
  • Jan 1, 1573

    Tycho Brahe

    Tycho Brahe
    Tycho observed a supernova now known as ``Tycho's supernova'', and made the most precise observations of stellar and planetary positions then known.
  • Christiaan Huygens

    Christiaan Huygens
    Huygens proposed that Saturn was surrounded by a solid ring, "a thin, flat ring, nowhere touching, and inclined to the ecliptic." Using a 50 power refracting telescope that he designed himself, Huygens also discovered the first of Saturn's moons, Titan.
  • Edmond Halley

    Edmond Halley
    Halley used his theory of cometary orbits to predict that the comet of 1682 (later named ``Halley's comet'') was periodic.
  • Johann Gottfried Galle

    Johann Gottfried Galle
    first person to observe Neptune, based on calculations by French mathematician, Urbain Le Verrier; however, Neptune's discovery is usually credited to Le Verrier and English astronomer, John Crouch Adams, who first predicted its position
  • Maximilian Wolf

    Maximilian Wolf
    He discovered hundreds of asteroids using photography
  • Clyde Tombaugh

    Clyde Tombaugh
    Clyde William Tombaugh was an American astronomer. Although he is best known for discovering the dwarf planet Pluto in 1930, the first object to be discovered in what would later be identified as the Kuiper belt, Tombaugh also discovered many asteroids
  • Jan Oort

    Jan Oort
    Measured the motions of stars in the Milky Way he was the first to find evidence for dark matter, when he found the mass of the galactic plane must be more than the mass of the material that can be seen.
  • Gerard Kuiper

    Gerard Kuiper
    He discovered carbon dioxide in the atmosphere of Mars and the existence of a methane-laced atmosphere above Saturn's satellite Titan.
  • William Fowler

    William Fowler
    He arried out extensive experimental studies of nuclear reactions of astrophysical significance; developed, with others, a complete theory of the formation of chemical elements in the universe
  • Sputnik 1

    Sputnik 1
    Sputnik 1 was the first artificial Earth satellite.The Soviet Union launched it into an elliptical low Earth orbit on 4 October 1957. It was visible all around the Earth and its radio pulses detectable. The surprise success precipitated the the American Sputnik crisis, began the Space Age and triggered the Space Race, a part of the larger Cold War. The launch ushered in new political, military, technological, and scientific developments.
  • James Elliot

    James Elliot
    Using a telescope in an airplane, Elliot led a team of Cornell University scientists to observe the planet Uranus when it passed between Earth and a star. Flying at night over a patch of the Indian Ocean where Uranus' shadow would be cast, he had the foresight to turn on his equipment more than a half-hour early. The move allowed him to record a series of slight dimmings that provided the first evidence of Uranus' rings.
  • Kip Thorne

    Kip Thorne
    He contributed to the theoretical understanding of black holes and gravitational radiation; co-founded the Laser Interferometer Gravitational Wave Observatory Project (LIGO)