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Feb 19, 1473
Copernicus
-He came up with the heliocentric system, putting the sun at the center of our system
-His ideas, including the revealation that the Earth rotates on its axis, were too different for most of the scholars of his time to accept http://kids.librarypoint.org/early_astronomers -
Feb 15, 1564
Galileo Galilei
-He had his own ideas on how motion really worked and devised a telescope that could enlarge objects up to 20 times
-He was able to use this telescope to prove the truth of the Copernican system of heliocentrism
- He spread it to the public that the sun is the center of the universe and for doing so, received life in prison http://kids.librarypoint.org/early_astronomers -
Dec 14, 1564
Tycho Brahe
-At the predicted time on August 21st, 1560, a total solar eclipse led him to regard astronomy as "something divine"
-Secretly studied astronomy while attenting law school
-While installing a laboratory at his uncle's castle, on the 11th of November 1572, he caught sight of the famous "new star" in Cassiopeia. He diligently measured its position, and printed an account of his observations in a tract entitled De Nova Stella http://www.nndb.com/people/559/000024487/ -
Dec 27, 1571
Johannes Kepler
-Kepler created these 3 laws of planetary motion
-Kepler's first Law: The orbit of a planet about the Sun is an ellipse with the Sun's center of mass at one focus.
-Kepler's second Law: A line joining a planet and the Sun sweeps out equal areas in equal intervals of time.
-Kepler's third Law: The squares of the periods of the planets are proportional to the cubes of their semi-major axes http://www.johanneskepler.com/ -
Isaac Newton
-He saw an apple fall from a tree on the farm and began pondering the laws of gravity
-He theorized that the forcev (gravity) that pulled objects toward the center of the Earth was the very same thing that held the Moon in orbit around the Earth http://www.nndb.com/people/864/000024792/
http://www.bellaonline.com/articles/art48510.asp -
Annie Jump Cannon
-HIred at Harvard to assist Edward Charles Pickering in the Henry Draper Catalog of Stellar Spectra
-Cannon found the system being used unworkable, and devised a different system, categorizing stars by letters of the alphabet, called the Harvard Spectral Classification Scheme which is now the official classification system
Cannon discovered about 300 stars and classified the photographic spectra of about 325,000 more, for which Time profiled her as "Census-taker of the sky"
http://www.nndb.com/ -
George Hale
-He invented the spectroheliograph in 1889, which allowed him to photograph the sun in broad daylight
-In1899 he helped found the American Astronomical Society
-He founded the Mount Wilson Observatory and was its director until 1923 http://www.nndb.com/people/672/000036564/ -
Henrietta Swan Leavitt
-While working at the Harvard College Observatory, she discovered 1,777 variable stars in the Magellanic Clouds, and noticed that (in oversimplified terms) brighter stars twinkle slower, and dimmer stars twinkle faster
-She then calculated the relationship between stars' luminosity and period of pulsation, called the Cepheid variable http://www.nndb.com/people/047/000170534/ -
Albert Einstein
-Einstein published his special theory of relativity
-This resulted in the shocking conclusion that time is not constant. Neither is weight or mass.
-He also said that when moving at high speeds, all of these things get compressed; only the speed of light remains the same. That happens because, said Einstein, energy is equal to mass times the speed of light squared, or E = mc2. http://www.pbs.org/wgbh/aso/databank/entries/bpeins.html -
Edwin Hubble
-Known as te father of observational cosmology
-In1917 he received a doctorate in astronomy from the University of Chicago
-He studied the skies at Mount Wilson Observatory, created a classification system for galaxies, and developed Hubble's Law in 1929
-Hubble campaigned for himself to win a Nobel Prize, but there was no category for astronomy http://www.nndb.com/people/673/000036565/ -
Gerald Kuiper
-He discovered two natural satellites of planets in the solar system, namely Uranus's satellite Miranda and Neptune's satellite Nereid
-He also discovered carbon dioxide in the atmosphere of Mars and the existence of a methane-laced atmosphere above Saturn's satellite Titan in 1944
-In the 1960s, he helped identify landing sites on the moon for the Apollo program. -
Bengt Georg Daniel Strömgren
-Sometimes called "The Great Dane" of scientists, he advanced mankind's understanding of what stars, and the huge space between them, are composed from
-Using quantum calculations of the opacity of stellar interiors, he determined in 1932 that hydrogen is the main component of stellar matter, and helium the lesser http://www.nndb.com/people/142/000173620/ -
Subrahmanyan Chandrasekhar
-He calculated that a star with a remaining mass greater than 1.4 times that of the Sun will, following its red giant phase, collapse and become a neutron star during a supernova explosion
-He also 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. www.nndb.com -
Grote Reber
-in 1937 he constructed the world's first radio telescope
-In 1944, he became the first to detect radio emissions from the Andromeda galaxy and the sun
-In the 1950s he turned his attention to cosmic radio waves at very low frequencies, which can only penetrate the Earth's ionosphere in certain areas and times of low solar activity http://www.nndb.com/people/090/000172571/ -
James Van Allen
-He discovered the Van Allen belts, two zones of electrically charged particles that surround the earth
-He combined his knowledge of rockets with balloon technology to create a “rockoon,” a balloon carrying a rocket. After the balloon reached its highest possible height, the rocket would go off, reaching much further heights. This enabled him to collect valuable information about Earth's atmosphere.
http://science.howstuffworks.com/dictionary/famous-scientists/physicists/james-alfred-van-allen- -
Sir Fred Hoyle
-In 1948 he formulated the Steady-State (or continuous creation) theory, rejecting the Big Bang theory and instead suggesting that the expansion of the universe is constant and interdependent with the creation of matter
-He also disdained the theory that life on Earth sprang from so-called "primordial soup", arguing instead that the introduction of pathogenic bacteria or viruses from outer space triggered the beginnings of life http://www.nndb.com/people/758/000113419/ -
E. Margaret Burbidge
-She developed a better explanation of how elements are formed by nuclear reactions inside stars
-She made notable contributions to the modern understanding of quasars, questioned the Big Bang theory, was the first woman to serve as Director of the Royal Observatory at Greenwich, and she was at the forefront of developing instrumentation for the Hubble Space Telescope. http://www.nndb.com/people/692/000168188/ -
Eugene Shoemaker
-In 1973, Shoemaker established the Palomar Planet-Crossing Asteroid Survey together with Eleanor Helin
-Their observations from 1973 to 1982 revealed three distinct types of earth-crossing objects distinguished by the placement of their orbits relative to that of the Earth
-Shoemaker estimated that there could be as many as 2,000 of these interstellar vagrants, any one of which might collide with the earth in the indeterminate future http://www.answers.com/topic/gene-shoemaker -
Thomas Mutch
-He was a professor at Brown University from 1960 until his death
-He published two books about the geology of the Moon and of Mars
-As head of the Viking surface photography team, he is quoted as commenting on the first pictures: "This is just an incredible scene. It looks safe and very interesting." http://en.wikipedia.org/wiki/Thomas_A._Mutch -
Aristarchus of Samos
310 BC
-He is 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, however, due to lackluster instruments, his data was incorrect http://www.nndb.com/people/756/000096468/ -
Aristotle
384 BC
-He is sometimes called the grandfather of science
-He elieved in a geocentric Universe and that the planets and stars were perfect spheres though Earth itself was not
-He also thought that the movements of the planets and stars must be circular since they were perfect and if the motions were circular, then they could go on forever http://kids.librarypoint.org/early_astronomers -
Eratosthenes
276 BC
-Eratosthenes was the first person to measure the circumference of the earth
-He may also have accurately calculated the distance from the earth to the sun and invented the leap day http://en.wikipedia.org/wiki/Eratosthenes -
Hipparchus
190 BC
-He made the capital discovery of the precession of the equinoxes in 130 BC
-Scientific geography originated with his invention of the method of fixing terrestrial positions by circles of latitude and longitude
-He also founded trigonometry http://www.nndb.com/people/842/000103533/ -
Ancient Greek Astronomy
-Greek astronomy refers to astronomy written in the Greek language in classical antiquity
-Greek astronomy is characterized from the start by seeking a rational, physical explanation for celestial phenomena
-Most of the constellations of the northern hemisphere derive are taken from Greek astronomy, as are the names of many stars and planets http://en.wikipedia.org/wiki/Greek_astronomy -
Pythagoras
580 BC
-He taught that the Earth was a sphere at the center of the universe
-He also recognised that the orbit of the Moon was inclined to the equator of the Earth
-He was one of the first to realise that Venus as an evening star was the same planet as Venus as a morning star http://www-history.mcs.st-and.ac.uk/Biographies/Pythagoras.html
