#p <o>astronomer<nat>Polish<n>Nicolaus Copernicus<b>1473 Feb 19<d>1543 May 24
#e <t>pub<au>Copernicus<n>heliocentric theory<d>1543 May<info>In 1512, Copernicus had written a short treatise on planetary motion. It was finally published in 1530. His final work, "De revolutionibus," was inspired in part by pope Leo X, who in 1514 had sent letters to European monarchs and prominent astronomers requesting advice on proposed changes to the calendar. Copernicus dedicated "De revolutionibus" to pope Paul III, acknowledging that his views were controversial. Unbeknownst to him, his publisher added a preface stating that his heliocentric theory was only a model which was used to explain motions, and disclaiming the idea that the earth actually revolved around the sun. Copernicus got to see his published book on his deathbed on the day he died.
#p <o>astronomer<nat>Italian<o>physicist<n>Galileo Galilei<sur>Galileo<b>1564 Feb 15<d>1642
#e <t>obs<au>Galileo<n>Jupiter's four large moons<d>1610 Jan 7
#e <t>pub<au>Galileo<tit>Dioptrice<d>1611
#p <o>astronomer<nat>German<n>Johannes Kepler<b>1571 Dec 27<d>1630
#e <t>theory<d>1595<au>Kepler<n>nested Platonic solids<info>Kepler thought the distances of the planets from the sun could be explained by nesting the six known planets' spheres between the five Platonic solids.
#e <t>theory<au>Kepler<n>laws of planetary motion<d>1609
#e <t>meeting<d>1600 Feb 4<n>Kepler and Brahe meet<c>Prague
#p <nat>English<o>astronomer<n>Sir John Herschel<b>1792<d>1871<fa>William Herschel
#e <t>obs<n>Uranus<d>1781 Mar 13<au>William Herschel
// 19th century
#e <t>obs<n>asteroid 1 Ceres<d>1801 Jan 1<info>the largest and first discovered asteroid<info>discovered by G. Piazzi
#e <t>obs<n>asteroid 2 Pallas<d>1802 Mar<info>the 2nd largest asteroid and 2nd asteroid discovered<info>discovered by Heinrich Olbers
#e <t>obs<n>asteroid 3 Juno<d>1804<info>the 3rd asteroid discovered<info>discovered by K. Harding
#e <t>obs<n>asteroid 4 Vesta<d>1845<info>the 3rd largest asteroid<info>Vesta appears to have a basaltic crust overlying an olivine mantle.
#e <t>obs<n>asteroid 5<d>1845<info>discovered by Karl Hencke
#e <t>obs<n>Neptune<d>1846 Sep 23
#e <t>obs<d>1877<n>Phobos and Deimos<c>U.S.<info>Asaph Hall, of U.S. Naval Observatory, discovers Mars' two moons.
// 20th century
#e <t>obs<n>Pluto<d>1930 Feb 18<info>by Clyde Tombaugh
#e <t>obs<n>Dactyl, satellite of asteroid 243 Ida<d>1993 Aug 28<info>imaged by Galileo probe
#e <t>observation<d>1998 Nov 17<n>Leonid meteor shower<info>Occuring every year on November 17, the Leonid meteor shower occurs when earth crosses the orbit of comet Tempel-Tuttle. The comet has a 33.2-year orbital period, with a maximum in the meteor shower occuring after each time the comet crosses earth's orbit. Such "meteor storms" occured in 902, 1799, 1833, and 1966. In 1899 no sharp peak in Leonid activity was noted. In 1933, it is believed to have happened over an unihabited part of the earth. The 1998 storm occured over central Asia and was much smaller than expected.
// Hubble
#p <nat>American<o>astronomer<n>Edwin Hubble<b>1889 Nov 20<d>1953 Sep 28<c>Chicago<mov>1920(2)<c>California
#e <t>obs<d>1923<n>existence of galaxies proven<c>Mount Wilson<au>Hubble<info>Hubble settled a long debate by demonstrating that the Andromeda "nebula" was actually a galaxy outside our own Milky Way and that many other such galaxies exist.
#e <t>theory<d>1925<n>classification of galaxies<au>Hubble<info>Hubble devised a classification scheme for the structure of galaxies that is still in use today in modified form.
#e <t>theory<d>1929<n>Hubble's law<au>Hubble<info>Hubble's law states that the more distant a galaxy is, the faster it is receding from us. The fundamental cosmological quantity known as Hubble's constant is derived from this law.