Timeline of Planetary Discoveries

  • 5000 BCE

    Gods in the Sky

    To early humans, the sky was where the gods dwelt and so early priests were holy men who interpreted their divine will through a careful study of astronomy mixed with religion.
  • 2500 BCE

    Constellations were invented

    Constellations were invented
    During this period in Mesopotamia, the constellations of Leo, Taurus, Scorpius, Gemini, Capricorn, and Sagittarius were invented, with these zodiac constellations also marking the path of the Sun, Moon, and planets throughout the year.
  • 2137 BCE

    Chinese record earliest known solar eclipse.

    Chinese record earliest known solar eclipse.
    Chinese record earliest known solar eclipse.
  • 1450 BCE

    The Egyptians start to use sundials.

    The Egyptians start to use sundials.
    The Egyptians start to use sundials.
  • 450 BCE

    Stars are suns

    Stars are suns
    Greek philosopher Anaxagoras suggest that the stars are actually suns, similar to our own, but located at such vast distances that we are unable to feel their heat back on Earth. His theory attracted disapproval from religious groups, though, and he was subsequently exiled from Athens.
  • 150

    Ptolemy

    Ptolemy
    Ptolemy states his geocentric theory of the solar system.
    https://www.britannica.com/biography/Ptolemy
  • 500

    Aryabhata

    Aryabhata
    Aryabhata makes many computations about the earth He computed the circumference of the earth, the regularity of eclipses of the sun and moon, and and how long the earths revolution around the sun is.
    http://www.famous-mathematicians.com/aryabhata/
  • 800

    Ja'far Muhammad ibn Musa ibn Shakir hypothesizes of gravity.

    Ja'far Muhammad ibn Musa ibn Shakir hypothesizes of gravity.
    Ja'far Shakir hypothesizes that celestial bodies are subject to the same physics laws as Earth and suggests that there is a force of attraction between celestial bodies.
    http://islamicencyclopedia.org/islamic-pedia-topic.php?id=543
  • 1514

    Copernicus states his heliocentric theory of the solar system.

    Copernicus states his heliocentric theory of the solar system.
    Copernicus states his heliocentric theory of the solar system. Most things revolve around the sun.
    http://www.pas.rochester.edu/~blackman/ast104/copernican9.html
  • 1514

    We go around the sun

    We go around the sun
    When virtually everyone believed Earth was the center of the universe, Polish scientist Nicolaus Copernicus (1473-1543) proposed that the planets instead revolved around the sun. Although his model wasn't completely correct, it formed a strong foundation for future scientists to build on and improve mankind's understanding of the motion of heavenly bodies.
    https://www.biography.com/people/nicolaus-copernicus-9256984
  • Kepler states his first two laws

    Kepler states his first two laws
  • Galileo Galilei and the Telescope

    Galileo Galilei and the Telescope
    The science of astronomy took a huge leap forward with the invention of the optical telescope and its use to study the night sky. Galileo Galilei was the first to use it systematically to observe celestial objects and record his discoveries.
    https://www.atnf.csiro.au/outreach/education/senior/astrophysics/galileo.html
  • Galileo Galilei discovers Jupiter's moons and Saturns rings

    Galileo Galilei discovers Jupiter's moons and Saturns rings
    Galileo Galilei discovers Jupiter's moons and Saturns rings, disproving part of Ptolemy's theory of the solar system
    http://solar-center.stanford.edu/galileo/
  • Jupiter is discovered by Galileo

    Jupiter is discovered by Galileo
    Jupiter is discovered by Galileo Jupiter is the largest planet in our solar system. It is one-tenth the size of the sun and ten times the size of the earth.
    http://nineplanets.org/jupiter.html
  • Jupiter's moon Io discovered by Galileo

    Jupiter's moon Io discovered by Galileo
    Jupiter's moon Io discovered by Galileo
    https://solarsystem.nasa.gov/planets/io
  • Europa discovered by Galileo

    Europa discovered by Galileo
    Jupiter's moon Europa discovered by Galileo.
    https://solarsystem.nasa.gov/planets/europa
  • The Milky Way

    The Milky Way
    The Milky Way was thought to be a strand of light in the nights sky. Galileo Galilei first resolved the band of light into individual stars with his telescope in 1610. Until the early 1920s, most astronomers thought that the Milky Way contained all the stars in the Universe.
  • Galileo discovered Saturn

    Galileo discovered Saturn
    Galileo was the first to observe Saturn with a telescope in 1611.
  • Kepler states his third empirical law

    Kepler states his third empirical law
    Kepler states his third empirical law The ratio of the squares of the periods of any two planets is equal to the ratio of the cubes of their average distances from the sun.
  • Christiaan Huygens indentifies the rings of Saturn

    Christiaan Huygens indentifies the rings of Saturn
    Christiaan Huygens indentifies the rings of Saturn.
    https://www.decodedscience.org/christiaan-huygens-discovered-saturns-rings/519
  • Cassini computes the speed at which Jupiter, Mars, and Venus rotate.

    Cassini computes the speed at which Jupiter, Mars, and Venus rotate.
    Cassini computes the speed at which Jupiter, Mars, and Venus rotate.
    https://www.space.com/18902-giovanni-cassini.html
  • Newton Theorizes about gravity

    Newton Theorizes about gravity
    Newton Theorizes about gravity Gravity keeps planets in their orbits. Without it they would be flung into deep space. Centrifugal force is the other factor that keeps planets in their orbits. Without it they would be drawn into the sun.
    http://www.thestargarden.co.uk/Newtons-theory-of-gravity.html
  • Huygens contemplates life

    Huygens contemplates life
    Huygens speculated in detail about life on other planets. In his book, Cosmotheoros, he imagined a universe brimming with life, much of it very similar to life on seventeenth century Earth.
    https://www.space.com/16070-christiaan-huygens.html
  • Halley predicts the path of Halley's comet

    Halley predicts the path of Halley's comet
    Halley predicts the path of Halley's comet Halley predicts the path of Halley's comet and figures out its return path in 1757. A comet is a chunk of rock and ice orbiting the sun. When passing close by the sun, a bright tail appears made of ice and rock coming off of the comet.
    https://www.space.com/19878-halleys-comet.html
  • Uranus found

    Uranus found
    William Herschel in the course of an observation on 13 March 1781, realised that one celestial body he had observed was not a star, but a planet, Uranus.
  • First recorded meteor shower

    First recorded meteor shower
    A meteor shower is when meteoroids come in contact with the earth's atmosphere. Meteoroids are small bodies of rock moving through the solar system.
    http://www.history.com/this-day-in-history/first-meteor-shower-on-record
  • Giuseppe Piazzi discovers Ceres

    Giuseppe Piazzi discovers Ceres
    Giuseppe Piazzi discovers Ceres: First discovered asteroid
    Asteroids are a rocks a few miles across that orbit the sun. Most of them orbit in clusters, between the orbits of Mars and Jupiter.
    https://dawn.jpl.nasa.gov/DawnCommunity/flashbacks/fb_04.asp
  • Pluto is discovered

    Pluto is discovered
    Pluto is discovered It is different from the outer planets because it is terrestrial and hs no rings. The other outer planets have rings and are gaseous and very large. Pluto is more like the inner planets: rocky and small.
    http://www.history.com/this-day-in-history/pluto-discovered
  • Classification of galaxies

    Classification of galaxies
    Astronomer Edwin Hubble revolutionized the field of astrophysics. His research helped prove that the universe is expanding, and he created a classification system for galaxies that has been used for several decades.
    https://www.biography.com/people/edwin-hubble-9345936
  • Probability of Life

    Probability of Life
    The Drake Equation, as it has become known, was first presented by Frank Drake in 1961 and identifies specific factors thought to play a role in the development of such civilizations.
    http://www.seti.org/drakeequation
  • Star Trek

    Star Trek
    Star Trek first appeared on TV in 1966. It was the first TV show to introduce space travel, including multiple galaxies, to popular culture. It followed a team of space travellers, Captain James T. Kirk and the crew of the Starship Enterprise explore the galaxy and defend the United Federation of Planets.
  • Apollo 8 Launched

    Apollo 8 Launched
    Apollo 8 takes first pictures of the sphere of the earth https://www.nasa.gov/mission_pages/apollo/missions/apollo8.html
  • The Moon

    The Moon
    Neil Armstrong and Buzz Aldrin walk on the Moon as part of the Apollo 11 mission.
  • Evidence of an ocean is discovered on Jupiter's moon Europa

    Evidence of an ocean is discovered on Jupiter's moon Europa
    Evidence of an ocean is discovered on Jupiter's moon Europa
    https://www.space.com/34172-europa-subsurface-ocean-what-we-know.html
  • Hubble Space Telescope Launched

    Hubble Space Telescope Launched
    NASA's Hubble Space Telescope was launched April 24, 1990, on the space shuttle Discovery from Kennedy Space Center in Florida.
    The Hubble Space Telescope was designed to provide clear and deep views of distant galaxies and stars and most of the planets in our solar system. Hubble's domain extends from the ultraviolet, through the visible, and to the near-infrared.
    https://www.nasa.gov/mission_pages/hubble/story/index.html
  • 51 Pegasi b

    51 Pegasi b
    The first exoplanet is found.
    51 Pegasi b is an extrasolar planet approximately 50 light-years away in the constellation of Pegasus. It was the first exoplanet to be discovered orbiting a main-sequence star, the Sun-like 51 Pegasi, and marked a breakthrough in astronomical research.
    https://en.wikipedia.org/wiki/51_Pegasi_b
  • Cassini-Huygens enters space

    Cassini-Huygens enters space
    Cassini–Huygens is an unmanned spacecraft sent to the planet Saturn. Cassini is the fourth space probe to visit Saturn and the first to enter orbit. It has studied the planet and its many natural satellites since arriving there in 2004. The spacecraft was launched on October 15, 1997, and entered orbit around Saturn on July 1, 2004.
    https://saturn.jpl.nasa.gov/
  • The International Space Station

    The International Space Station
    The International Space Station (ISS) is a space station, or a habitable artificial satellite, in low Earth orbit. Its first component launched into orbit in 1998, and the ISS is now the largest man-made body in low Earth orbit and can often be seen with the naked eye from Earth.
    https://www.nasa.gov/audience/forstudents/5-8/features/nasa-knows/what-is-the-iss-58.html
  • Hubble Space Telescope discovers exoplanet

    Hubble Space Telescope discovers exoplanet
    Astronomers using NASA's Hubble Space Telescope made the first direct detection of the atmosphere of a planet orbiting a star outside our solar system and have obtained the first information about its chemical composition. The unique observations demonstrate that it is possible with Hubble and other telescopes to measure the chemical makeup of exoplanet atmospheres and to potentially search for chemical markers of life beyond Earth.
  • Spitzer Space Telescope

    Spitzer Space Telescope
    The Spitzer Space Telescope is the final mission in NASA's Great Observatories Program. Spitzer is designed to detect infrared radiation, which is primarily heat radiation and set to study the 'Hot Jupiters' in the surrounding solar systems. The Spitzer Space Telescope was the first telescope to directly capture light from exoplanets, namely the "hot Jupiters" HD 209458 b and TrES-1b.
    http://www.spitzer.caltech.edu/mission/32-Mission-Overview
  • First information gathered from Mars rovers

    First information gathered from Mars rovers
    First information gathered from Mars rovers.
    https://mars.nasa.gov/mer/home/
  • And then there were eight...

    And then there were eight...
    As far as everyone was concerned Pluto was the ninth but that all changed with the discovery of Eris, a planet which was 27 per cent bigger than Pluto.
    Both Pluto and Eris were then declassified as 'dwarf planets', and the number of official planets in our solar system dropped from nine to eight.
    https://www.nasa.gov/audience/forstudents/k-4/stories/nasa-knows/what-is-pluto-k4.html
  • New Horizons Launched

    New Horizons Launched
    New Horizons is an interplanetary space probe that was launched as a part of NASA's New Frontiers program. The spacecraft was launched in 2006 with the primary mission to perform a flyby study of the Pluto system in 2015, and a secondary mission to fly by and study one or more other Kuiper belt objects (KBOs) in the decade to follow.
    https://futurism.com/images/new-horizons-to-pluto-and-beyond-infographic/
  • Dark Matter

    Dark Matter
    In the summer of 2006, astronomers made an announcement that helped humans understand the cosmos a little better: They had direct evidence confirming the existence of dark matter -- even though they still can't say what exactly the stuff is.
    https://www.space.com/20930-dark-matter.html
  • Organic Molecules are Found

    Organic Molecules are Found
    Hubble takes a picture of the exoplanet Formalhaut b, the first visual image of an exoplanet and finds organic molecules on the exoplanet. The telescope’s 100,000th orbit around Earth is celebrated.
  • Kepler Space Observatory

    Kepler Space Observatory
    Kepler is a space observatory launched by NASA to discover Earth-size planets orbiting other stars. Named after astronomer Johannes Kepler, the spacecraft was launched on March 7, 2009, into an Earth-trailing orbit.
    http://www.keplermission.com/
  • Moon Water Confirmed

    Moon Water Confirmed
    India's Chandrayaan-1 satellite confirmed the presence of water on the moon in September 2009, building on flyby observations by other probes on their way elsewhere. Although the lunar surface is still drier than Earth's driest desert, evidence of water is there, hinting at a solar wind interaction with the moon's surface that produces water molecules.
    http://news.nationalgeographic.com/news/2009/11/091113-water-on-the-moon.html
  • Juno Launched

    Juno Launched
    Juno is a NASA space probe orbiting the planet Jupiter. The spacecraft was launched from Cape Canaveral Air Force Station on August 5, 2011, as part of the New Frontiers program, and entered a polar orbit of Jupiter on July 5, 2016 begin a scientific investigation of the planet.
    https://www.missionjuno.swri.edu/
  • Landing on a comet

    Landing on a comet
    The Rosetta mission became the first to successfully land on a comet in 2014.
    It was seen as an historic moment as it allowed scientists to study the materials that make up a comet for the first time.
    Ongoing tests from the comet hope to find out more about how the universe was formed.
    http://www.esa.int/Our_Activities/Space_Science/Rosetta/Mission_complete_Rosetta_s_journey_ends_in_daring_descent_to_comet