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Feb 19, 1473
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 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 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 observed a supernova now known as ``Tycho's supernova'', and made the most precise observations of stellar and planetary positions then known. -
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
Halley used his theory of cometary orbits to predict that the comet of 1682 (later named ``Halley's comet'') was periodic. -
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
He discovered hundreds of asteroids using photography -
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
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
He discovered carbon dioxide in the atmosphere of Mars and the existence of a methane-laced atmosphere above Saturn's satellite Titan. -
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 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
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
He contributed to the theoretical understanding of black holes and gravitational radiation; co-founded the Laser Interferometer Gravitational Wave Observatory Project (LIGO)
