Astronomy Milestones

Astronomy is the scientific study of the Universe and the bodies it contains (excluding Earth). Astronomers are the scientists who study astronomy.

• Year / Milestone
  585 BC — First prediction of eclipse of the Sun
  130 BC — Hipparchus calculated distance and size of Moon.
  AD 1543 — Copernicus showed that the Sun is at the centre of the Solar System.
  1609 — Johannes Kepler described laws of planetary motion
  1610 — Galileo Gailei discovered moons of Jupiter
  1655 — Christiaan Huygens discovered Titan, moon of Saturn
  1668 — Isaac Newton built first reflecting telescope
  1687 — Isaac Newton published theories of motions of planets, etc
  1705 — Edmond Halley predicted return of comet
  1671-84 — Giovanni Cassini discovered four moons of Saturn
  1774 — Charles Messier compiled star catalogue
  1781 — William Herschel discovered 7th planet, Uranus
  1801 — First asteroid, Ceres, discovered by Giuseppe Piazzi
  1846 — Johann Galle and Urbain Le Verrier discovered 8th planet Neptune
  1787-89 — Herschel finds two moons of Uranus and two of Saturn
  1839-40 — First photographs of the Moon
  1894 — Flagstaff Observatory, Arizona, was founded
  1905 — Einstein’s Special Theory of Relativity was first proposed
  1908 — Giant and dwarf stars were described
  1923 — Galaxies beyond the Milky Way were proved
  1927 — Big Bang theory was proposed for first time
  1930 — Pluto, the 9th planet, was discovered by Clyde Tombaugh
  1959 — First photographs of the far side of the Moon taken by Soviet satellite Luna 3
  1961 — First quasars were discovered
  1967 — First pulsars were identified
  1971 — Black hole was detected
  1973 — Skylab space laboratory was launched
  1976 — Rings of Uranus were discovered
  1977 — Voyager deep space probes were launched
  1971 — Mariner 9 spacecraft maped Mars
  1980 — Voyager 1 explored Saturn
  1978 — Space proes Pioneer 1 and 2 reached Venus
  1985-89 — Voyager 2 discovers moons of Uranus and Neptune
  1994 — Comet Shoemaker-Levy observed crashing into Jupiter
  1997 — Mars pathfinder was landed
  1997 — Cassini probe was launched to Saturn
  1998 — International Space Station construction was started
  1999 — Chandra X-Ray Observatory was launched
  2003 — Galileo probe was deliberately crash-landed on Jupiter
  2006 — New Horizons space probe was launched to Pluto