History of Astronomy Electronic Timeline

  • 190

    Hipparchus (B.C.)

    Hipparchus (B.C.)
    -also developed the system of epicycles (where everything in space moved in perfect circles) for the planets that both agreed with observation, and preserved the Earth-centered universe of Aristotle. http://www.windows2universe.org/people/ancient_epoch/hipparchus.html
  • 276

    Eratosthenes (B.C.)

    Eratosthenes (B.C.)
    -found the distance between the tropics to be 11/83 rds. of the meridian circle, which gives 23 degrees, 5', 20'' for the obliquity of the ecliptic. -His astronomical poem Hermes began apparently with the birth and exploits of Hermes, then passed to the legend of his having ordered the heavens, the zones and the stars, and gave a history of the latter. http://www.nndb.com/people/712/000095427/
  • 310

    Aristarchus of Samos (B.C.)

    Aristarchus of Samos (B.C.)
    -famous as having been the first to maintain that the earth moves round the sun. -His method of estimating the relative lunar and solar distances is geometrically correct, though the instrumental means at his command rendered his data erroneous. http://www.nndb.com/people/756/000096468/
  • 384

    Aristotle (B.C.)

    Aristotle (B.C.)
    -Aristotle offered the world an internally consistent physics and cosmology of hitherto uncomparable breadth and explanatory power, which was to endure for more than 1200 years. -Aristotle adopted with some modifications the geocentric planetary model of Eudoxus,but ascribed physical reality to the planetary spheres. http://www.astro.umontreal.ca/~paulchar/grps/site/images/aristotle.html
  • 582

    Pythagoras (B.C.)

    Pythagoras (B.C.)
    -taught that the Earth was a sphere at the center of the universe. http://9waysmysteryschool.tripod.com/sacredsoundtools/id13.html
  • Jan 1, 624

    Ancient Greek Astronomy (General) (B.C.)

    Ancient Greek Astronomy (General) (B.C.)
    (624-230 B.C.)
    -ancient civilizations watched the heavens as patterns in the sky that allowed the to know when the seasons changed - among other things. They built great stone monuments called astronomical observatories such as Stonehenge as celestials clocks to mark these events and the passage of time. -They believed their gods lived in the skies and named them and the constellations after them. http://www.crystalinks.com/greekastronomy.html
  • Jan 1, 1473


    -develop and demonstrate the validity of the mathematical model which reflected the physical reality of the solar system. He also had to overcome centuries-old and well entrenched concepts of the universe. -his calculations proved that, in contradiction to Ptolemaic theory, the distance between the earth and the moon is the same no matter whether the moon is full or in one of its quarters. http://info-poland.buffalo.edu/classroom/kopernik/copernicus.shtml
  • Jan 1, 1546

    Tycho Brahe

    Tycho Brahe
    -its insensible parallax to be no terrestrial exhalation, as commonly supposed, but a body traversing planetary space. It included, besides, an account of the Tychonic plan of the cosmos, in which a via media was sought between the Ptolemaic and Copernican systems. The earth retained its immobility; but the five planets were made to revolve round the sun, which, with its entire cortege, annually circuited the earth, the sphere of the fixed stars per http://www.nndb.com/people/559/000024487/
  • Jan 1, 1564

    Galileo Galilei

    Galileo Galilei
    -His achievements include improvements to the telescope and consequent astronomical observations -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 http://www.crystalinks.com/galileo.html
  • Jan 1, 1571

    Johannes Kepler

    Johannes Kepler
    -he believed that the Earth was at rest, that the Sun and the Moon revolved about it, and that all the other planets revolved around the Sun http://www.myastrologybook.com/Johannes-Kepler.htm
  • Isaac Newton

    Isaac Newton
    -According to the well-known story, it was on seeing an apple fall in his orchard at some time during 1665 or 1666 that Newton conceived that the same force governed the motion of the Moon and the apple. -He calculated the force needed to hold the Moon in its orbit, as compared with the force pulling an object to the ground http://www.jimal-khalili.com/blog/the-lucasian-chair.html http://www.newton.ac.uk/newtlife.html
  • Annie Jump Cannon

    Annie Jump Cannon
    -In 1901 she published a catalogue of 1,122 southern stars, which represented a sequence of continuous change from the blue-white stars of types O and B, with their strong helium lines, through types A, F, G, and K, characterized hydrogen and various metal lines, to the red stars of type M with their spectral bands of titanium and carbon oxides. -her scheme was adopted by all observatories. http://www.daviddarling.info/encyclopedia/C/Cannon.html
  • George Hale

    George Hale
    -invented the spectroheliograph, founded the Astrophysical Journal (and invented the word astrophysics), founded the Yerkes Observatory (which then housed the world's largest working telescope) -Through Hale's leadership and foresight, Mt. Wilson Observatory dominated the world of astronomy in the first half of the 20th century http://www.mwoa.org/hale.html
  • Henrietta Swan Leavitt

    Henrietta Swan Leavitt
    -discovered that certain variable stars have a cycle that corresponds to their luminosity; the brighter the star, the longer the period. -she was able to determine that the intrinsic brightness of these stars is predictable. By comparing that value to the apparent brightness, the difference can then be used to calculate their distance from Earth. http://www.wwu.edu/depts/skywise/a101_historicalfigures.html
  • Albert Einstein

    Albert Einstein
    -areas of major impact concern the nature of light, gravity, and time. -The strange nature of time is explained in Einstein's Theory of Special Relativity. It shows how time is not absolute, but elastic, stretching or compressing depending on the individual observer's point of view. As bizzare as that may seem, this is one of the most tested and successful theories in history. http://www.wwu.edu/depts/skywise/a101_historicalfigures.html
  • Edwin Hubble

    Edwin Hubble
    -This movement suggests the Universe is getting bigger. If it is getting bigger, that means it use to be smaller. This discovery led astronomers to the Big Bang Theory http://www.wwu.edu/depts/skywise/a101_historicalfigures.html
  • Gerard Kuiper

    Gerard Kuiper
    -Kuiper suggested that there was a belt of comet-like debris at the edge of our solar system, a theory that was proven true 20 years after his death. http://www.windows2universe.org/people/today/kuiper.html
  • Bengt Georg Daniel Stromgren

    Bengt Georg Daniel Stromgren
    -found relations between the gas density, the luminosity of the star -In the 1930s and 1940s Strömgren engaged in pioneering work on emission nebulae – huge clouds of interstellar gas and dust shining by their own light. http://www.answers.com/topic/bengt-str-mgren
  • Subrahmanyan Chandrasekhar

    Subrahmanyan Chandrasekhar
    -responsible for much of the modern baseline understanding of stellar evolution — the origins, structure, dynamics, and deaths of stars. -showed that a star will collapse once it has exhausted its nuclear fuel, a process that will end in most stars because of the outward pressure exerted by a degenerate gas; but that stars more enormous than about three solar masses can collapse into themselves, becoming black holes. http://www.nndb.com/people/960/000099663/
  • Grote Reber

    Grote Reber
    -found radio emissions from the Milky Way, the Sun, and a source in Cassiopeia, and made the first radio map of the sky. -worked on telescopes in Hawaii and Tasmania after he was done with his government job http://amazing-space.stsci.edu/resources/explorations/groundup/lesson/bios/reber/
  • James Van Allen

    James  Van Allen
    -pathbreaking astrophysicist best known for his work in magnetospheric physics. -Van Allen was involved in the first four Explorer probes, the first Pioneers, several Mariner efforts, and the orbiting geophysical observatory. http://www.time.com/time/covers/0,16641,19590504,00.html
  • Sir Fred Hoyle

    Sir Fred Hoyle
    -acknowledged to be one of the most creative scientists of the 20th century. -also the founder of the Institute of Astronomy at Cambridge. http://spacetheology.blogspot.com/2009/04/fred-hoyle-black-cloud.html
  • E. Magaret Burbidge

    E. Magaret Burbidge
    -astronomer with the Hubble Space Telescope. -studied the spectra of galaxies, nuclear reactions at the center of stars, and conducted spectroscopic surveys of quasars. http://www.physics.usyd.edu.au/foundation/iss/iss_history.shtml
  • Eugene Shoemaker

    Eugene Shoemaker
    -He received a National Medal of Science in 1992 and in 1993 co-discovered Comet Shoemaker-Levy 9 which collided with Jupiter in 1994. -One of his aspirations was to be an astronaut and go to the Moon but was thwarted by a medical condition. http://www.romesg.com/?p=624
  • Thomas Mutch

    Thomas Mutch
    -led the Lander Imaging Team from the Viking Mission to Mars. -NASA administrator Dr. Robert A. Frosch honored Tim by renaming the Viking 1 Lander spacecraft on Mars, "The Thomas A. Mutch Memorial Station." http://www.brown.edu/Departments/Geology/colloquia/mutch.html
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    History of Astonomy Electronic Timeline