The first year of King Yih of Zhou's reign is marked by a solar eclipse.

Tags: Zhou Dynasty, Astronomy, Solar Eclipse, Royal Court, Cosmology, Observation

The first historic solar eclipse is recorded in China.

Tags: Astronomy, Eclipse, Zhou Dynasty, Cosmology, Celestial Events, Historical Records

June 15, 763 BC: A solar eclipse on this date is used to fix the chronology of the Ancient Near East.

Tags: Astronomy, Chronology, Eclipse

Estimated date of the impact that created the Kaali crater

Tags: Astronomy, Geology, Natural Disaster, Estonia

April 6, 648 BC: Earliest Greek-chronicled solar eclipse.

Tags: Ancient greece, Astronomy, Eclipse, Chronology, Observation, Natural Phenomena, Cosmology

28 May 585 BC: A solar eclipse occurs as predicted by Thales, while Alyattes is battling Cyaxares. This leads to a truce. This is one of the cardinal ...

Tags: Astronomy, Solar Eclipse, Ancient greece, Lydia, Median Empire, Warfare

4 December 502 BC: Solar eclipse darkens Egypt (computed, no clear historical record of observation).

Tags: Astronomy, Solar Eclipse, Celestial Events, Observation

Athens adopts a 19-year cycle of synchronizing solar and lunar calendars.

Tags: Ancient greece, Calendars, Astronomy, Timekeeping

The 19 year lunar cycle is introduced into the Babylonian calendar.

Tags: Astronomy, Calendars, Ancient Mesopotamia, Timekeeping, Mathematics, Religion

On May 15, Chinese mathematicians observed and recorded the passage of the Halley's Comet.

Tags: Astronomy, Comets, Observation, Mathematics, Celestial Bodies, Zhou Dynasty

Hypsicles, Greek mathematician and astronomer

Tags: Mathematics, Astronomy, Ancient greece, Geometry, Number Theory, Scientific Advancement

Hipparchus discovers precession of Earth's equinoxes and compiles first trigonometric tables.

Tags: Astronomy, Mathematics, Ancient greece, Trigonometry, Measurement

Canopus stele of Ptolemy III implements the leap year in Egypt. Leap year not formally recognized until Caesar in 55 BC.

Tags: Astronomy, Calendar Reform, Ptolemaic Dynasty, Timekeeping, Ancient greece

An empty shell Glyph for zero, is found on a Maya numerals Stela, from Chiapa de Corzo, Chiapas. Independently invented by Claudius Ptolemy, in the se...

Tags: Maya Civilization, Mathematics, Ancient Mesoamerica, Astronomy, Pre-Columbian America

Liu Xin, Chinese astronomer, mathematician and politician (b. c. 50 BC)

Tags: Astronomy, Mathematics, Han Dynasty, Scientific Advancement, Astrology, Cosmology

Thrasyllus of Mendes, Greek grammarian and astronomer

Tags: Ancient greece, Roman Empire, Astronomy, Grammar, Scholar, Mathematics

An eclipse on 30 April over North Africa is recorded by Pliny the Elder in his Natural History.

Tags: Ancient rome, Natural History, Astronomy, Scientific Observation, Pliny the Elder, Roman Empire, Eclipse

Halley's Comet is visible.

Tags: Astronomy, Comets, Celestial Events, Natural Phenomena, Roman Empire, Early Science

Zhang Heng, Chinese mathematician, astronomer, inventor, and statesman (d. 139)

Tags: Astronomy, Mathematics, Han Dynasty, Zhang Heng, Cosmology

Zhang Heng of China invents the world's first water-powered armillary sphere.

Tags: Astronomy, Zhang Heng, Han Dynasty

1048 – Abū Rayhān al-Bīrūnī of Persia writes more than a hundred books on many different topics.

Tags: Islamic Golden Age, Mathematics, Astronomy, Philosophy, Scholarship

– The Remaining Signs of Past Centuries is written by Abū Rayhān al-Bīrūnī.

Tags: Islamic Golden Age, Astronomy, Mathematics, Calendars, History of Science, Middle Ages

– Ibn Samh of Al-Andalus builds a geared mechanical astrolabe.

Tags: Islamic Golden Age, Astronomy, Astrolabe, Mathematics, Al-Andalus, Scientific Instruments, Middle Ages

1087 – Abū Ishāq Ibrāhīm al-Zarqālī (Arzachel) builds the equatorium and universal latitude-independent astrolabe.

Tags: Astronomy, Astrolabe, Islamic Golden Age, Scientific Instruments, Mathematics, Al-Andalus

– Abū Rayhān al-Bīrūnī writes Kitab al-qanun al-Mas'udi

Tags: Astronomy, Mathematics, Islamic Golden Age, Middle Ages, Cosmology

In 1095, Shen Kuo made significant scientific advances, including theories on land formation, climate change, and true north, along with improvements ...

Tags: Astronomy, Climate Change, Archaeology, Scientific Revolution, Song Dynasty, Shen Kuo

a large supernova is observed by astronomers, the remnants of which would form the Crab Nebula.

Tags: Astronomy, Supernova, Celestial Events, Cosmology, Scientific Observation, Middle Ages, Astrophysics

al-Zarqālī in Islamic Spain discovers the apsidal precession of the Sun.

Tags: Astronomy, Islamic Golden Age, Mathematics, Al-Andalus, Middle Ages, Astrology

Chinese official Su Song is sent on a diplomatic mission to the Liao dynasty and discovers that the Khitan calendar is more mathematically accurate th...

Tags: Astronomy, Song Dynasty, Liao Dynasty, Su Song, Cultural Exchange

Malik Shah I reforms the Iranian Calendar.

Tags: Calendar, Astronomy, Shah, Seljuk Empire, Timekeeping, Mathematics

– The Chinese mechanical engineer and astronomer Su Song incorporates an escapement mechanism and the world's first known chain drive to operate the a...

Tags: Clockmaking, Astronomy, Mechanical Engineering, Song Dynasty

Pluto moves inside Neptune's orbit until July 23, 1503, according to modern orbital calculations.

Tags: Astronomy, Planetary Science, Solar System, Orbital Mechanics, Celestial Bodies, Mathematics

Nilakantha Somayaji discovers an infinite series for π.: 101–102 

Tags: Mathematics, Astronomy, Pi, Infinite Series

Nilakantha Somayaji develops a model similar to the Tychonic system. His model has been described as mathematically more efficient than the Tychonic s...

Tags: Astronomy, Mathematics, Scientific Revolution, Heliocentric Theory, Planetary Motion

Copernicus writes Commentariolus, and proclaims the Sun the center of the Solar System.

Tags: Astronomy, Scientific Revolution, Renaissance, Cosmology, Heliocentrism, Nicolaus Copernicus, Scientific Thought

Copernicus publishes his theory that the Earth and the other planets revolve around the Sun

Tags: Astronomy, Scientific Revolution, Mathematics, Cosmology, Heliocentrism, Nicolaus Copernicus, Renaissance, Scientific Theory

Galileo Galilei born on February 15

Tags: Astronomy, Renaissance, Scientific Revolution, Galileo Galilei, Physics, Heliocentrism, Scientific Method, Italian Renaissance, Telescope, Cosmology

Supernova SN 1572 is observed by Tycho Brahe in the Milky Way.

Tags: Astronomy, Tycho Brahe, Milky Way, Supernova, Scientific Revolution, Renaissance, Cosmology, Observational Astronomy

Pope Gregory XIII issues the Gregorian calendar. The last day of the Julian calendar was Thursday, 4 October 1582 and this was followed by the first d...

Tags: Calendar, Astronomy, Timekeeping, Gregorian Calendar, Religious Authority, Renaissance

William Gilbert: Earth's magnetic field.

Tags: Astronomy, Physics, Magnetism, Scientific Revolution, Renaissance, Experimentation, Earth Science

Supernova SN 1604 is observed in the Milky Way.

Tags: Astronomy, Supernova, Cosmology, Scientific Revolution, Tycho Brahe, Celestial Events, Observation, Milky Way

Johannes Kepler starts investigating elliptical orbits of planets.

Tags: Astronomy, Scientific Revolution, Heliocentrism, Planetary Motion, Johannes Kepler, Physics, Mathematics, Cosmology

Earliest record of an optical telescope.

Tags: Scientific Revolution, Optics, Astronomy, Dutch Republic, Hans Lippershey, Telescope, Observation

Johannes Kepler: first two laws of planetary motion.

Tags: Astronomy, Scientific Revolution, Planetary Motion, Physics, Mathematics, Johannes Kepler, Tycho Brahe

The Orion Nebula is identified by Nicolas-Claude Fabri de Peiresc of France.

Tags: Astronomy, Scientific Observation, Renaissance, Telescope, Discovery

Galileo Galilei and Simon Marius observe Jupiter's Galilean moons.

Tags: Astronomy, Scientific Revolution, Heliocentric Theory, Telescope, Galileo Galilei, Renaissance, Planetary Science, Scientific Observation

Galileo Galilei: Sidereus Nuncius: telescopic observations.

Tags: Scientific Revolution, Astronomy, Telescope, Galileo Galilei, Heliocentrism, Renaissance, Scientific Method

John Napier introduces the logarithm to simplify calculations.

Tags: Mathematics, Scientific Revolution, Navigation, Astronomy

Niccolò Zucchi describes experiments with a bronze parabolic mirror trying to make a reflecting telescope.

Tags: Scientific Revolution, Astronomy, Optics, Telescope, Scientific Instruments

Johannes Kepler: third law of planetary motion.

Tags: Scientific Revolution, Astronomy, Planetary Motion, Johannes Kepler, Mathematics, Cosmology

Giovanni Riccioli renames the lunar maria.

Tags: Astronomy, Renaissance, Moon, Cartography, Scientific Revolution

Christiaan Huygens describes the true shape of the rings of Saturn.

Tags: Astronomy, Scientific Revolution, Physics, Cosmology, Telescope, Christiaan Huygens, Observation

Christiaan Huygens first to observe surface details of Mars.

Tags: Astronomy, Mars, Scientific Observation, Telescope, Scientific Revolution, Planetary Science, Christiaan Huygens

James Gregory publishes designs for a reflecting telescope.

Tags: Astronomy, Optics, Telescopes, Scientific Revolution, Instrumentation

First functional reflecting telescope constructed by Isaac Newton.

Tags: Optics, Isaac Newton, Scientific Revolution, Astronomy, Telescope, Instrumentation

The first known operational reflecting telescope is built by Isaac Newton.

Tags: Optics, Telescopes, Isaac Newton, Scientific Revolution, Astronomy, Physics

Greenwich Observatory commissioned.

Tags: Astronomy, Royal Society, Navigation, Scientific Revolution, Measurement, Timekeeping

Ole Rømer: first measurement of the speed of light.

Tags: Physics, Optics, Measurement, Astronomy, Scientific Revolution, Light

Thomas Godfrey and John Hadley independently develop the octant

Tags: Navigation, Astronomy, Scientific Revolution, Maritime History, Exploration

Immanuel Kant: Gaseous Hypothesis in Universal Natural History and Theory of Heaven.

Tags: Philosophy, Cosmology, Enlightenment, Immanuel Kant, Astronomy, Theoretical Physics

Mikhail Lomonosov: discovery of the atmosphere of Venus.

Tags: Astronomy, Enlightenment, Scientific Revolution, Planetary Science, Venus

Charles Messier: publishes catalogue of astronomical objects (Messier Objects) now known to include galaxies, star clusters, and nebulae.

Tags: Astronomy, Scientific Revolution, Galaxies, Cosmology, Observation

William Herschel announces discovery of Uranus, expanding the known boundaries of the Solar System for the first time in modern history.

Tags: Astronomy, Scientific Revolution, Planetary Science, Solar System, Discovery, Enlightenment, Telescope, Cosmology

Italian astronomer Giuseppe Piazzi discovers the dwarf planet Ceres.

Tags: Astronomy, Planetary Science, Solar System

Friedrich Bessel: first successful measure of stellar parallax (to star 61 Cygni).

Tags: Astronomy, Physics, Scientific Revolution, Observational Astronomy, Stars, Measurement

Christian Doppler: Doppler effect.

Tags: Physics, Astronomy, Sound, Light

Johann Gottfried Galle and Heinrich Louis d'Arrest: discovery of Neptune.

Tags: Astronomy, Planets, Solar System

Asaph Hall discovers the moons of Mars.

Tags: Astronomy, Space Exploration, Planetary Science, Mars

April: Halley's Comet returns.

Tags: Astronomy, Comets, Popular Culture, Celestial Events

Williamina Fleming: the first white dwarf, 40 Eridani B

Tags: Astronomy, Cosmology, Stellar Evolution, Astrophysics, Spectroscopy

Vesto Slipher: galactic redshifts

Tags: Astronomy, Cosmology, Galaxies, Observational Astronomy, Expansion of the Universe, Physics

Henrietta Swan Leavitt: Cepheid variable period-luminosity relation

Tags: Astronomy, Cosmology, Astrophysics, Edwin Hubble

Karl Schwarzschild: discovery of the Schwarzschild radius leading to the identification of black holes

Tags: Physics, Cosmology, Relativity, Black Holes, Theoretical Physics, Astronomy, German Science

First experimental evidence for the General theory of relativity obtained by Arthur Eddington.

Tags: Physics, Relativity, Astronomy, Scientific Revolution, Theory, Albert Einstein, Cosmology

Edwin Hubble: the discovery that the Milky Way is just one of many galaxies

Tags: Astronomy, Cosmology, Edwin Hubble, Galaxies, Milky Way, Universe, Observational Astronomy, Expansion of the Universe

Cecilia Payne-Gaposchkin: Discovery of the composition of the Sun and that hydrogen is the most abundant element in the Universe

Tags: Astronomy, Cosmology, Astrophysics, Elements, 20th Century Science

Georges Lemaître: Theory of the Big Bang

Tags: Cosmology, Physics, Astronomy, Relativity, Expansion of the Universe, Scientific Theory, Global Impact

Edwin Hubble: Hubble's law of the expanding universe

Tags: Astronomy, Cosmology, Edwin Hubble, 20th Century Science, Universe, Expansion, Space

February 18: Clyde Tombaugh discovers Pluto.

Tags: Astronomy, Space Exploration, Planets, Astrophysics, Solar System, Discovery

Karl Guthe Jansky discovers the first astronomical radio source, Sagittarius A

Tags: Astronomy, Radio Astronomy, Astrophysics, Cosmology, Milky Way

October 7: The USSR probe Luna 3 sends back the first ever photos of the far side of the Moon.

Tags: Space Exploration, Cold War, Soviet Union, Moon, Astronomy, Space Race

Riccardo Giacconi and his team discover the first cosmic x-ray source, Scorpius X-1

Tags: Astronomy, Astrophysics, Cosmology, Space Exploration, Observational Astronomy

November 28: NASA launches the Mariner 4 space probe from Cape Kennedy toward Mars to take television pictures of that planet in July 1965.

Tags: Space Exploration, NASA, Mars, Space Race, Planetary Science, Cold War, Astronomy

Jocelyn Bell Burnell and Antony Hewish discover first pulsar

Tags: Astronomy, Astrophysics, Radio Astronomy, Cosmology, 20th Century Science, Cambridge University

Vela nuclear test detection satellites discover the first gamma-ray burst

Tags: Astronomy, Astrophysics, Space Exploration, Cold War, Particle Physics

The first space station, Salyut 1, is launched.

Tags: Space Exploration, Space Race, Cold War, Soviet Union, Space Station, Astronomy

December 3: Pioneer 10 sends back the first close-up images of Jupiter.

Tags: Space Exploration, Astronomy, Jupiter, NASA, Planetary Science, Space Race

March 29: First close-up images of Mercury by Mariner 10. The Terracotta Army of Qin Shi Huang is discovered at Xi'an, China.

Tags: Space Exploration, Archaeology, Planetary Science, Qin Dynasty, Astronomy, Cultural Heritage, Celestial Bodies

August 20: Voyager 2 launched by NASA.

Tags: Space Exploration, NASA, Planetary Science, Voyager Program, Astronomy, Space Race, Exploration

June 22: Discovery of Pluto's moon Charon.

Tags: Astronomy, Space Exploration, Planetary Science, Kuiper Belt, Solar System, Celestial Bodies, Discovery

November 13: Voyager 1 takes the first close-up pictures of Saturn.

Tags: Space Exploration, Astronomy, Planetary Science, Voyager Program, NASA, Spacecraft

Donald C. Backer et al. discover the first millisecond pulsar

Tags: Astronomy, Astrophysics, Radio Astronomy, Space Exploration, Cosmology

January 24: First close-up images of the planet Uranus

Tags: Space Exploration, Astronomy, Planetary Science, Voyager Program, NASA, Solar System, Spacecraft

March: Return of Halley's Comet.

Tags: Astronomy, Comets, Space Exploration, Scientific Observation, Popular Culture

August 25: Voyager 2 makes its closest approach to Neptune and its largest moon, Triton.

Tags: Space Exploration, Voyager Program, Planetary Science, Astronomy, Spacecraft, NASA, Solar System

April 24 – May 20: Launch of the Hubble Space Telescope.

Tags: Space Exploration, Astronomy, Telescopes, NASA, Astrophysics, Cosmology, Space Race

July 11: A solar eclipse of record totality occurs in the Northern hemisphere. It is seen by 20 million people in Hawaii, Mexico, and Colombia.

Tags: Astronomy, Solar Eclipse, Scientific Observation, Hawaii

Aleksander Wolszczan and Dale Frail observe the first pulsar planets (this was the first confirmed discovery of planets outside the Solar System)

Tags: Astronomy, Astrophysics, Exoplanets, Planetary Science, Solar System, Space Exploration

Michel Mayor and Didier Queloz definitively observe the first extrasolar planet around a main sequence star

Tags: Astronomy, Exoplanets, Planetary Science, Astrophysics, Space Exploration, Observational Astronomy, 20th Century Science

Supernova Cosmology Project and the High-Z Supernova Search Team: discovery of the accelerated expansion of the Universe and dark energy

Tags: Cosmology, Astronomy, Supernova, Universe, Expansion, Observation, Research

July 14: A powerful solar flare, later named the Bastille Day event, causes a geomagnetic storm on Earth.

Tags: Astronomy, Space, Earth Science

First surface images of Saturn's moon Titan.

Tags: Space Exploration, Astronomy, Planetary Science, Exploration

July 29: Michael E. Brown confirms the discovery of the dwarf planet Eris.

Tags: Astronomy, Planetary Science, Solar System, Space Exploration, Kuiper Belt

The International Astronomical Union creates the first formal definition of a planet, which drops Pluto's classification as a planet.

Tags: Astronomy, Planetary Science, Dwarf Planets, Solar System, Cosmology

The first solar sail based spacecraft, IKAROS.

Tags: Space Exploration, Spacecraft, Aerospace Engineering, Astronomy

NASA launches spacecraft to visit Jupiter and Mars.

Tags: Space Exploration, NASA, Astronomy, Planetary Science, Jupiter, Spacecraft

The US rover, Curiosity, takes a selfie on Mars and finds evidence of an ancient streambed of water on the Red Planet.

Tags: Space Exploration, Mars, Planetary Science, Astronomy, Robotics, NASA, Geology

November 12: The Rosetta spacecraft's Philae probe becomes the first to successfully land on a comet.

Tags: Space Exploration, Comets, Astronomy, Spacecraft

Liquid water is found on Mars.

Tags: Space Exploration, Astronomy, Planetary Science, Mars, Astrobiology, NASA

First close-up images of Ceres and Pluto.

Tags: Space Exploration, Astronomy, Planetary Science, Solar System, NASA, Dwarf Planets

February 11: Detection of gravitational waves by LIGO confirmed.

Tags: Physics, Astronomy, Gravitational Waves, General Relativity, LIGO, Black Holes, Cosmology

July 4: Juno enters orbit around Jupiter

Tags: Space Exploration, Astronomy, Planetary Science, NASA, Jupiter, Spacecraft

October 28: 'Oumuamua, the first known interstellar object, is identified.

Tags: Astronomy, Space Exploration, Discovery, Solar System, Cosmology

Gravitational wave signal GW170817 is observed by the LIGO/Virgo collaboration. This is the first instance of a gravitational wave event observed to h...

Tags: Astronomy, Astrophysics, Gravitational Waves, LIGO, Scientific Breakthrough, Cosmology, Space Exploration

April 10: The Event Horizon Telescope takes the first ever image of a black hole, at the core of galaxy Messier 87. Fossil fragments found in the Call...

Tags: Astronomy, Black Holes, Event Horizon Telescope, Paleontology, Human Evolution

New Horizons takes the first close up image of a classical kuiper belt object.

Tags: Space Exploration, Astronomy, Kuiper Belt, Planetary Science, Solar System, Spacecraft, NASA

July 30: NASA successfully launches its Mars 2020 rover mission to search for signs of ancient life and collect samples for return to Earth.

Tags: Space Exploration, Mars, NASA, Astronomy, Planetary Science

Phosphine, a potential sign of life, was detected in Venus' atmosphere, while perfectly preserved remains of a cave bear dating back up to 39,500 year...

Tags: Astronomy, Paleontology, Venus, Microbiology, Discovery

December 18: Media outlets report that astronomers have detected a radio signal, BLC1, apparently from the direction of Proxima Centauri, the closest...

Tags: Astronomy, Space Exploration, Astrobiology

December 21: A great conjunction of Jupiter and Saturn occurs, with the two planets separated in the sky by 0.1 degrees. This is the closest conjuncti...

Tags: Astronomy, Planets, Celestial Events, Space, Observational Astronomy, Scientific Observation

China launches Chang'e 5 and becomes the third country after the US and the Soviet Union to return samples of the moon.

Tags: Space Exploration, Lunar Exploration, Astronomy, Space Race

NASA and SOFIA (Stratospheric Observatory for Infrared Astronomy) discover about 12 US fl oz (350 ml) of surface water in one of the Moon's largest vi...

Tags: Space Exploration, Astronomy, Moon, NASA

December 1: The Arecibo Telescope of the Arecibo Observatory collapses, just weeks after the announcement of its planned demolition.

Tags: Astronomy, Radio Astronomy, Space Exploration, Infrastructure

June 7: The Juno spacecraft performs its only flyby of Jupiter's moon Ganymede, the first flyby of the moon by any spacecraft in over 20 years.

Tags: Space Exploration, Astronomy, Jupiter, NASA

March 20: WHL0137-LS "Earendel" imaged by Hubble Space Telescope, the earliest and most distant known star.

Tags: Astronomy, Space Exploration, Stars, Cosmology, Astrophysics, Discovery

May 12: Sagittarius A*, supermassive black hole at Galactic Center, imaged by Event Horizon Telescope.

Tags: Astronomy, Astrophysics, Event Horizon Telescope, Cosmology, Observation

July 11: James Webb Space Telescope takes Webb's First Deep Field, oldest and highest resolution image of the universe to date.

Tags: Space Exploration, Astronomy, Cosmology, Astrophysics, Telescopes

September 26: Double Asteroid Redirection Test demonstrates capabilities on asteroid (65803) Didymos I Dimorphos.

Tags: Space Exploration, Astronomy, Aerospace Engineering, NASA