The History of Astronomy

  • 16 BCE

    Babylonian Tablets

    Babylonian Tablets
    Ancient Babylonian tablets show knowledge of the distinction between the moving planets and the stars, and the recognition that the movement of planets are regular and periodic.
  • 15 BCE

    Hindu Rigveda

    Hindu Rigveda
    describes the origin of the universe in which a “cosmic egg” or Brahmanda, containing the Sun, Moon, planets and the whole universe, expands out of a single concentrated point before subsequently collapsing again, reminiscent of the much later Big Bang and oscillating universe theories.
  • 5 BCE

    The Greek philosopher Anaxagoras

     The Greek philosopher Anaxagoras
    becomes arguably the first to formulate a kind of molecular theory of matter, and to regard the physical universe as subject to the rule of rationality or reason.
  • 5 BCE

    Leucippus and Democritus found the school of Atomism

     Leucippus and Democritus found the school of Atomism
    holds that the universe is composed of very small, indivisible and indestructible building blocks known as atoms, which then form different combinations and shapes in an infinite void.
  • 4 BCE

    The Greek philosopher Aristotle

    The Greek philosopher Aristotle
    describes a geocentric universe in which the fixed, spherical Earth is at the centre, surrounded by concentric celestial spheres of planets and stars. Although he portrays the universe as finite in size, he stresses that it exists unchanged and static throughout eternity.
  • 4 BCE

    The Greek philosopher Heraclides

    The Greek philosopher Heraclides
    proposes that the apparent daily motion of the stars is created by the rotation of the Earth on its axis once a day, and that the Sun annually circles a central Earth, while the other planets orbit the Sun
  • 3 BCE


    proved that the Earth was round, and made a remarkably accurate calculation of its circumference and its tilt
  • 3 BCE

    The Stoic philosophers of ancient Greece

    The Stoic philosophers of ancient Greece
    assert a kind of “island universe” in which a finite cosmos is surrounded by an infinite void
  • 2 BCE

    Hipparchus of Nicea

    Hipparchus of Nicea
    makes the first measurement of the precession of the equinoxes, and compiles the first star catalogue
  • 2

    Claudius Ptolemaeus

    Claudius Ptolemaeus
    describes a geocentric model, largely based on Aristotelian ideas, in which the planets and the rest of the universe orbit about a stationary Earth in circular epicycles
  • Sep 12, 1543

    Nicolaus Copernicus

     Nicolaus Copernicus
    proposes that the Earth rotates on its axis once daily and travels around the Sun once a year, and demonstrates that the motions of celestial objects can be explained without putting the Earth at rest in the centre of the universe.
  • Johannes Kepler

    Johannes Kepler
    Johannes Kepler
  • Galileo Galilei

     Galileo Galilei
    develops an astronomical telescope powerful enough to indentify moons orbiting Jupiter, sunspots on the Sun and the different phases of Mercury, all of which are instrumental in convincing the scientific community of the day that the heliocentric Copernican model of the Solar System is superior to the geocentric Ptolemiac model.
  • Sir Isaac Newton

    Sir Isaac Newton
    he establishes the three Laws of Motion (“a body persists its state of rest or of uniform motion unless acted upon by an external unbalanced force”; “force equals mass times acceleration”; and “to every action there is an equal and opposite reaction”) and the Law of Universal Gravitation (that every particle in the universe attracts every other particle according to an inverse-square formula) that were not to be improved upon for more than two hundred years.
  • Halley's comet

    Halley's comet
    Halley of england correctly predicts the return of a comet
  • Uranus

    The discovery of Uranus by Herschel
  • Messier objects

    Messier objects
    Messier discovers galaxies, nebula and star clusters while looking for comets. He compiles a catalogue of these objects
  • Mount Wilson Observatory

    	Mount Wilson Observatory
    its created for studying the sun
  • Theory of Relativity

    Theory of Relativity
    Albert Einstein introduces special Theory of Relativity in paper Electrodynamics of Moving Bodies.
  • Galaxies

    Hubble shows that galaxies exist outside the Milky Way galaxy.
  • Yuri Gagarin

    Yuri Gagarin
    First man in space
  • John Glenn

    John Glenn
    John Glenn becomes first American man to orbit Earth.
  • Apollo 11 mission.

     Apollo 11 mission.
    Armstrong and Aldrin walk on the Moon as part of Apollo 11 mission.
  • Galileo space probe

    Galileo space probe
    Galileo space probe reaches Jupiter.
  • Chandra X-ray Observatory

    Chandra X-ray Observatory
    Chandra X-ray Observatory is put into orbit. Col. Eileen Collins becomes first woman shuttle commander.
  • water on Mars

    water on Mars
    New evidence found for water on Mars.
  • The Shenzhou 5 spacecraft

    The Shenzhou 5 spacecraft
    is launched from Jiuquan Satellite Launch Center in China. It carries Yang Liwei who becomes the first man sent into space by the Chinese space program. China sets goals for an eventual manned space station and a manned mission to the Moon.
  • Spirit Rover Lands on Mars

    Spirit Rover Lands on Mars
    After parachuting through the atmosphere and then bouncing to a stop using giant air bags, the Mars rover Spirit lands on the red planet in a location known as Gusev crater.
  • First Impact With a Comet

    First Impact With a Comet
    After a journey of 174 days, the Deep Impact space probe fulfills its mission by slamming into a comet known as Tempel 1. The probe impacts the comet at a speed of 10.3 kilometers (6.3 miles) per second.
  • First Comet Samples Returned to Earth

    First Comet Samples Returned to Earth
    After a journey of nearly seven years and 2.9 billion miles (4.6 billion kilometers), NASA's Stardust mission successfully comes to a conclusion in the desert salt flats of the Utah Test and Training Range. The capsule safely parachutes to the ground after collecting dust and particle samples from comet Wild 2. The samples are collected by the probe in the comet's coma within 147 miles (236 kilometers) of the comet’s nucleus
  • SpaceX

    A company called SpaceX becomes the first private company to launch a spacecraft to orbit and return it safely to the Earth