Timeline of astronomy
This article needs additional citations for verification. (November 2023) |
This is a timeline of astronomy. It covers ancient, medieval, Renaissance-era, and finally modern astronomy.
Antiquity
750 BCE
Mayan astronomers discover an 18.7-year cycle in the rising and setting of the Moon. From this they created the first almanacs – tables of the movements of the Sun, Moon, and planets for the use in astrology. In 6th century BCE Greece, this knowledge is used to predict eclipses.
585 BCE
Thales of Miletus is said to have predicted a solar eclipse.
467 BCE
400 BCE
Around this date, Babylonians use the zodiac to divide the heavens into twelve equal segments of thirty degrees each, the better to record and communicate information about the position of celestial bodies.[4]
387 BCE
Plato, a Greek philosopher, founds a school (the Platonic Academy) that will influence the next 2000 years. It promotes the idea that everything in the universe moves in harmony and that the Sun, Moon, and planets move around Earth in perfect circles.
380 BCE
Aristotle, a Greek polymath, described gravity as a downward motion which moves towards the centre of the earth.[5]
270 BCE
Aristarchus of Samos proposes heliocentrism as an alternative to the Earth-centered universe. His heliocentric model places the Sun at its center, with Earth as just one planet orbiting it. However, there were only a few people who took the theory seriously.
240 BCE
The earliest recorded sighting of Halley's Comet is made by Chinese astronomers. Their records of the comet's movement allow astronomers today to predict accurately how the comet's orbit changes over the centuries.
170 BCE
Hipparchus was a Greek astronomer, geographer, and mathematician. He is considered the founder of trigonometry, but is most famous for his incidental discovery of the precession of the equinoxes. Hipparchus was born in Nicaea, Bithynia, and probably died on the island of Rhodes,
70 BCE
]4 BCE
The astronomer Shi Shen is believed to have cataloged 809 stars in 122 constellations, and he also made the earliest known observation of sunspots.
140 CE
Middle ages
400 CE
The Hindu cosmological time cycles explained in the Surya Siddhanta, give the average length of the sidereal year (the length of the Earth's revolution around the Sun) as 365.2563627 days, which is only 1.4 seconds longer than the modern value of 365.256363004 days.[8] This remains the most accurate estimate for the length of the sidereal year anywhere in the world for over a thousand years.
499 CE
Indian mathematician-astronomer
628 CE
Indian mathematician-astronomer Brahmagupta, in his Brāhmasphuṭasiddhānta, first recognizes gravity as a force of attraction. He gives methods for calculations of the motions and places of various planets, their rising and setting, conjunctions, and calculations of the solar and lunar eclipses.
773 CE
The
777 CE
830 CE
The first major
850 CE
928 CE
The earliest surviving astrolabe is constructed by astronomer Nastulus.[13]
1030 CE
Al-Biruni discussed the Indian heliocentric theories of Aryabhata, Brahmagupta and Varāhamihira in his Ta'rikh al-Hind (Indica in Latin). Biruni stated that the followers of Aryabhata consider the Earth to be at the center. In fact, Biruni casually stated that this does not create any mathematical problems.[14]
1031 CE
Al-Sijzi, a contemporary of Al-Biruni, defended the theory that Earth rotates on its axis.
1054 CE
Chinese astronomers record the sudden appearance of a bright star. Native-American rock carvings also show the brilliant star close to the Moon. This star is the Crab supernova exploding.
1070 CE
Abu Ubayd al-Juzjani published the Tarik al-Aflak. In his work, he indicated the so-called "equant" problem of the Ptolemic model. Al-Juzjani even proposed a solution to the problem. In al-Andalus, the anonymous work al-Istidrak ala Batlamyus (meaning "Recapitulation regarding Ptolemy"), included a list of objections to the Ptolemic astronomy.
One of the most important works in the period was Al-Shukuk ala Batlamyus ("Doubts on Ptolemy"). In this, the author summed up the inconsistencies of the Ptolemic models. Many astronomers took up the challenge posed in this work, namely to develop alternate models that evaded such errors.
1126 CE
1150 CE
Indian mathematician-astronomer Bhāskara II, in his Siddhanta Shiromani, calculates the longitudes and latitudes of the planets, lunar and solar eclipses, risings and settings, the Moon's lunar crescent, syzygies, and conjunctions of the planets with each other and with the fixed stars, and explains the three problems of diurnal rotation. He also calculates the planetary mean motion, ellipses, first visibilities of the planets, the lunar crescent, the seasons, and the length of the Earth's revolution around the Sun to 9 decimal places.
1190 CE
Nur ad-Din al-Bitruji proposed an alternative geocentric system to Ptolemy's. He also declared the Ptolemaic system as mathematical, and not physical. His alternative system spread through most of Europe during the 13th century, with debates and refutations of his ideas continued to the 16th century.[15][16]
1250 CE
Mu'ayyad al-Din al-Urdi develops the Urdi lemma, which is later used in the Copernican heliocentric model.
His Tusi-couple is later used in the Copernican model.Tusi's student Qutb al-Din al-Shirazi, in his The Limit of Accomplishment concerning Knowledge of the Heavens, discusses the possibility of heliocentrism.
1350 CE
Renaissance and Age of Enlightenment
16th century
1500 CE
Nilakantha Somayaji proposes a model very similar to the Tychonic system and his equation for the centre for the planets Mercury and Venus were the most accurate until Johannes Kepler
1543 CE
Nicolaus Copernicus publishes De revolutionibus orbium coelestium containing his theory that Earth travels around the Sun. However, he complicates his theory by retaining Plato's perfect circular orbits of the planets.
1572 CE
A brilliant supernova (SN 1572 – thought at the time to be a comet) is observed by Tycho Brahe, who proves that it is traveling beyond Earth's atmosphere and therefore provides the first evidence that the heavens can change.
17th century
1608 CE
Dutch eyeglass maker
1609 CE
Johannes Kepler publishes his New Astronomy. In this and later works, he announces his three laws of planetary motion, replacing the circular orbits of Plato with elliptical ones. Almanacs based on Johannes' laws prove to be highly accurate.
1610 CE
Galileo Galilei publishes Sidereus Nuncius describing the findings of his observations with the telescope he built. These include spots on the Sun, craters on the Moon, and four satellites of Jupiter. Proving that not everything orbits Earth, he promotes the Copernican view of a Sun-centered universe.
1655 CE
As the power and the quality of the telescopes increase, Christiaan Huygens studies Saturn and discovers its largest satellite, Titan. He also explains Saturn's appearance, suggesting the planet is surrounded by a thin ring.
1663 CE
Scottish astronomer James Gregory describes his "gregorian" reflecting telescope, using parabolic mirrors instead of lenses to reduce chromatic aberration and spherical aberration, but is unable to build one.
1668 CE
Isaac Newton builds the first reflecting telescope, his Newtonian telescope.
1687 CE
Isaac Newton publishes his first copy of the book Philosophiae Naturalis Principia Mathematica, establishing the theory of gravitation and laws of motion. The Principia explains Kepler's laws of planetary motion and allows astronomers to understand the forces acting between the Sun, the planets, and their moons.
18th century
1705 CE
Edmond Halley calculates that the comets recorded at 76-year intervals from 1456 to 1682 are one and the same. He predicts that the comet will return again in 1758. When it reappears as expected, the comet is named in his honor.
1750 CE
French astronomer
1781 CE
Amateur astronomer William Herschel discovers the planet Uranus, although he at first mistakes it for a comet. Uranus is the first planet to be discovered beyond Saturn, which was thought to be the most distant planet in ancient times.
1784 CE
Charles Messier publishes his catalog of star clusters and nebulas. Messier draws up the list to prevent these objects from being identified as comets. However, it soon becomes a standard reference for the study of star clusters and nebulas and is still in use today.
19th century
1800 CE
William Herschel splits sunlight through a prism and with a thermometer, measures the energy given out by different colours. He notices a sudden increase in energy beyond the red end of the spectrum, discovering invisible infrared and laying the foundations of spectroscopy.
1801 CE
Italian astronomer Giuseppe Piazzi discovers what appears to be a new planet orbiting between Mars and Jupiter, and names it Ceres. William Herschel proves it is a very small object, calculating it to be only 320 km in diameter, and not a planet. He proposes the name asteroid, and soon other similar bodies are being found. We now know that Ceres is 932 km in diameter, and is now considered to be a dwarf planet.
1814 CE
Joseph von Fraunhofer builds the first accurate spectrometer and uses it to study the spectrum of the Sun's light. He discovers and maps hundreds of fine dark lines crossing the solar spectrum. In 1859 these lines are linked to chemical elements in the Sun's atmosphere. Spectroscopy becomes a method for studying what stars are made of.
1838 CE
Friedrich Bessel successfully uses the method of stellar parallax, the effect of Earth's annual movement around the Sun, to calculate the distance to 61 Cygni, the first star other than the Sun to have its distance from Earth measured. Bessel's is a truly accurate measurement of stellar positions, and the parallax technique establishes a framework for measuring the scale of the universe.
1843 CE
German amateur astronomer Heinrich Schwabe, who had been studying the Sun for the past 17 years, announces his discovery of a regular cycle in sunspot numbers - the first clue to the Sun's internal structure.
1845 CE
Irish astronomer William Parsons, 3rd Earl of Rosse completes the first of the world's great telescopes, with a 180-cm mirror. He uses it to study and draw the structure of nebulas, and within a few months discovers the spiral structure of the Whirlpool Galaxy.
French physicists
1846 CE
A new planet, Neptune, is identified by German astronomer Johann Gottfried Galle while searching in the position suggested by Urbain Le Verrier. Le Verrier has calculated the position and size of the planet from the effects of its gravitational pull on the orbit of Uranus. An English mathematician, John Couch Adams, also made a similar calculation a year earlier.
1868 CE
Astronomers notice a new bright emission line in the spectrum of the Sun's atmosphere during an eclipse. The emission line is caused by an element's giving out light, and British astronomer Norman Lockyer concludes that it is an element unknown on Earth. He calls it helium, from the Greek word for the Sun. Nearly 30 years later, helium is found on Earth.
1872 CE
An American astronomer Henry Draper takes the first photograph of the spectrum of a star (Vega), showing absorption lines that reveal its chemical makeup. Astronomers begin to see that spectroscopy is the key to understanding how stars evolve. William Huggins uses absorption lines to measure the redshifts of stars, which give the first indication of how fast stars are moving.
1895 CE
Konstantin Tsiolkovsky publishes his first article on the possibility of space flight. His greatest discovery is that a rocket, unlike other forms of propulsion, will work in a vacuum. He also outlines the principle of a multistage launch vehicle.
20th century
1901 CE
A comprehensive survey of stars, the Henry Draper Catalogue, is published. In the catalog, Annie Jump Cannon proposes a sequence of classifying stars by the absorption lines in their spectra, which is still in use today.
1906 CE
Ejnar Hertzsprung establishes the standard for measuring the true brightness of a star. He shows that there is a relationship between color and absolute magnitude for 90% of the stars in the Milky Way Galaxy. In 1913, Henry Norris Russell published a diagram that shows this relationship. Although astronomers agree that the diagram shows the sequence in which stars evolve, they argue about which way the sequence progresses. Arthur Eddington finally settles the controversy in 1924.
1910 CE
Williamina Fleming publishes her discovery of white dwarf stars.
1912 CE
Henrietta Swan Leavitt discovers the period-luminosity relation for Cepheid variables, whereas the brightness of a star is proportional to its luminosity oscillation period. It opened a whole new branch of possibilities of measuring distances on the universe, and this discovery was the basis for the work done by Edwin Hubble on extragalactic astronomy.
1916 CE
German physicist Karl Schwarzschild uses Albert Einstein's theory of general relativity to lay the groundwork for black hole theory. He suggests that if any star collapse to a certain size or smaller, its gravity will be so strong that no form of radiation will escape from it.
1923 CE
Edwin Hubble discovers a Cepheid variable star in the "Andromeda Nebula" and proves that Andromeda and other nebulas are galaxies far beyond our own. By 1925, he produces a classification system for galaxies.
1925 CE
Cecilia Payne-Gaposchkin discovers that hydrogen is the most abundant element in the Sun's atmosphere, and accordingly, the most abundant element in the universe by relating the spectral classes of stars to their actual temperatures and by applying the ionization theory developed by Indian physicist Meghnad Saha. This opens the path for the study of stellar atmospheres and chemical abundances, contributing to understand the chemical evolution of the universe.
1926 CE
1929 CE
Edwin Hubble discovered that the universe is expanding and that the farther away a galaxy is, the faster it is moving away from us. Two years later, Georges Lemaître suggests that the expansion can be traced to an initial "Big Bang".
1930 CE
By applying new ideas from subatomic physics, Subrahmanyan Chandrasekhar predicts that the atoms in a white dwarf star of more than 1.44 solar masses will disintegrate, causing the star to collapse violently. In 1933, Walter Baade and Fritz Zwicky describe the neutron star that results from this collapse, causing a supernova explosion.
Clyde Tombaugh discovers the dwarf planet Pluto at the Lowell Observatory in Flagstaff, Arizona. The object is so faint and moving so slowly that he has to compare photos taken several nights apart.
1932 CE
1938 CE
German physicist Hans Bethe explains how stars generate energy. He outlines a series of nuclear fusion reactions that turn hydrogen into helium and release enormous amounts of energy in a star's core. These reactions use the star's hydrogen very slowly, allowing it to burn for billions of years.
1944 CE
A team of German scientists led by
1947 CE
The US sent up the first
1948 CE
The largest telescope in the world, with a 5.08m (200 in) mirror, is completed at Palomar Mountain in California. At the time, the telescope pushes single-mirror telescope technology to its limits – large mirrors tend to bend under their own weight.
1957 CE
The Soviet Union launches the first artificial satellite, Sputnik 1, into orbit, beginning the space age. The US launches its first satellite, Explorer 1, four months later.
1958 CE
July 29 marks the beginning of the NASA (National Aeronautics and Space Administration), agency newly created by the United States to catch up with Soviet space technologies. It absorbs all research centers and staffs of the NACA (National Advisory Committee for Aeronautics), an organization founded in 1915.
1959 CE
The USSR and the US both launch probes to the Moon, but NASA's Pioneer probes all failed. The Soviet Luna program was more successful. Luna 2 crash-lands on the Moon's surface in September, and Luna 3 returns the first pictures of the Moon's farside in October.
1960 CE
1961 CE
Although in January with NASA's Mercury-Redstone 2 mission, the chimpanzee Ham became the first Hominidae in space, the USSR takes the lead in the space race as Yuri Gagarin becomes the first person to orbit Earth in April. NASA astronaut Alan Shepard becomes the first American in space a month later, but does not go into orbit, although he is the first person to land with himself still inside his spacecraft thus technically achieving the first complete human spaceflight by then FAI definitions.[22][23] John Glenn achieves orbit in early 1962.
1962 CE
Mariner 2 becomes the first probe to reach another planet, flying past Venus in December. NASA follows this with the successful Mariner 4 mission to Mars in 1965, both the US and the USSR send many more probes to planets through the rest of the 1960s and 1970s.
1963 CE
Dutch-American astronomer Maarten Schmidt measures the spectra of quasars, the mysterious star-like radio sources discovered in 1960. He establishes that quasars are active galaxies, and among the most distant objects in the universe.
1965 CE
1966 CE
Soviet Luna 9 probe makes the first successful soft landing on the Moon in January, while the US lands the far more complex Surveyor missions, which follows up to NASA's Ranger series of crash-landers, scout sites for possible crewed landings.
1967 CE
Jocelyn Bell Burnell and Antony Hewish detected the first pulsar, an object emitting regular pulses of radio waves. Pulsars are eventually recognized as rapidly spinning neutron stars with intense magnetic fields - the remains of a supernova explosion.
1968 CE
NASA's Apollo 8 mission becomes the first human spaceflight mission to enter the gravitational influence of another celestial body and to orbit it.
1969 CE
The US wins the race for the Moon as Neil Armstrong and Buzz Aldrin step onto the lunar surface on July 20. Apollo 11 is followed by five further landing missions, three carrying a sophisticated Lunar Roving Vehicle.
1970 CE
The Uhuru satellite, designed to map the sky at X-ray wavelengths, is launched by NASA. The existence of X-rays from the Sun and a few other stars has already been found using rocket-launched experiments, but Uhuru charts more than 300 X-ray sources, including several possible black holes.
1971 CE
The USSR launches its first space station Salyut 1 into orbit. It is followed by a series of stations, culminating with Mir in 1986. A permanent platform in orbit allows cosmonauts to carry out serious research and to set a series of new duration records for spaceflight.
1972 CE
1975 CE
The Soviet probe Venera 9 lands on the surface of Venus and sends back the first picture of its surface. The first probe to land on another planet, Venera 7 in 1970, had no camera. Both break down within an hour in the hostile atmosphere.
1976 CE
NASA's Viking 1 and Viking 2 space probes arrive at Mars. Each Viking mission consists of an orbiter, which photographs the planet from above, and a lander, which touches down on the surface, analyzes the rocks, and searches unsuccessfully for life.
1977 CE
On August 20 the
On September 5 The
1981 CE
Space Shuttle Columbia, the first of NASA's reusable Space Shuttles, makes its maiden flight, ten years in development, the Shuttle will make space travel routine and eventually open the path for a new International Space Station.
1983 CE
The first infrared astronomy satellite, IRAS, is launched. It must be cooled to extremely low temperatures with liquid helium, and it operates for only 300 days before the supply of helium is exhausted. During this time it completes an infrared survey of 98% of the sky.
1986 CE
NASA's spaceflight program comes to a halt when Space Shuttle Challenger explodes shortly after launch. A thorough inquiry and modifications to the rest of the fleet kept the shuttles on the ground for nearly three years.
The returning
1989 CE
The
1990 CE
The Hubble Space Telescope, the first large optical telescope in orbit, is launched using the Space Shuttle, but astronomers soon discovered that it is crippled by a problem with its mirror. A complex repair mission in 1993 allows the telescope to start producing spectacular images of distant stars, nebulae, and galaxies.
1992 CE
The Cosmic Background Explorer satellite produces a detailed map of the background radiation remaining from the Big Bang. The map shows "ripples", caused by slight variations in the density of the early universe – the seeds of galaxies and galaxy clusters.
The 10-meter
1995 CE
The first exoplanet, 51 Pegasi b, is discovered by Michel Mayor and Didier Queloz.
1998 CE
Construction work on a huge new space station named
The accelerated expansion was discovered during 1998, by two independent projects, the Supernova Cosmology Project and the High-Z Supernova Search Team, which both used distant type Ia supernovae to measure the acceleration.
21st century
2003 CE
Space Shuttle Columbia disintegrates upon reentry into Earth's atmosphere
2005 CE
2006 CE
2008 CE
2008 TC3 becomes the first Earth-impacting meteoroid spotted and tracked prior to impact.
2012 CE
(May 2) First visual proof of the existence of black holes is published. Suvi Gezari's team in Johns Hopkins University, using the Hawaiian telescope Pan-STARRS 1, record images of a supermassive black hole 2.7 million light-years away that is swallowing a red giant.[28]
2013 CE
In October 2013, the first extrasolar asteroid is detected around white dwarf star GD 61. It is also the first detected extrasolar body which contains water in liquid or solid form.[29][30][31]
2015 CE
On July 14, with the successful encounter of Pluto by NASA's New Horizons spacecraft, the United States became the first nation to explore all of the nine major planets recognized in 1981. Later on September 14, LIGO was the first to directly detect gravitational waves.[32]
2016 CE
Exoplanet Proxima Centauri b is discovered around Proxima Centauri by the European Southern Observatory, making it the closest known exoplanet to the Solar System as of 2016.
2017 CE
In August 2017, a
2019 CE
China's Chang'e 4 became the first spacecraft to perform a soft landing on the far side of the Moon.
In April 2019, the
India launched its second lunar probe called Chandrayaan-2 with an orbiter that was successful and a lander called Vikram along with a rover called Pragyan which failed just 2.1 km above the lunar south pole.
2020 CE
NASA launches Mars 2020 to Mars with a Mars rover and a small helicopter that was named Perseverance and Ingenuity by seventh grader Alexander Mather and eleventh grader Vaneeza Rupani respectively in a naming contest.[36][37] First human orbital spaceflight launched by a private company occurred when SpaceX Demo-2 carrying astronauts Bob Behnken and Doug Hurley was launched to the International Space Station.
References
- ISBN 978-0-6712-0158-6. Retrieved 1 June 2015.
- ISBN 978-0-6911-6592-9. Retrieved 1 June 2015.
- ISBN 0-7661-2826-1
- S2CID 122004678,
[T]he zodiac was introduced between −408 and −397 and probably within a very few years of −400.
- ISBN 978-0-521-56137-2.
- ^ "Vitruvius, On Architecture 7.8.3". lexundria.com. Retrieved 2023-04-07.
- ^ )
- ^ White, M.J. "Sidereal, tropical, and anomalistic years" (PDF). Retrieved 2016-05-16.
- ISBN 978-0-7139-9687-6.
- JSTOR 1005726
- ^ Dallal (1999), pg. 163
- ^ Dallal (1999), pg. 164
- ISBN 9780387310220.
- ^ Saliba (1999).
- ISBN 978-0-684-10114-9.
- ISBN 978-0-387-31022-0. (PDF version)
- ^ M. Gill (2005). Was Muslim Astronomy the Harbinger of Copernicanism? Archived 2006-04-21 at the Wayback Machine
- ^ UPPER AIR ROCKET SUMMARY V-2 NO. 20 Archived 15 July 2011 at the Wayback Machine. postwarv2.com
- ^ "The Beginnings of Research in Space Biology at the Air Force Missile Development Center, 1946–1952". History of Research in Space Biology and Biodynamics. NASA. Archived from the original on 25 January 2008. Retrieved 31 January 2008.
- ^ "V-2 Firing Tables". White Sands Missile Range. Archived from the original on 25 January 2008. Retrieved 31 January 2008.
- ^ "Science: Project Ozma," Time, April 18, 1960 (web version accessed 17 October 2017)
- ^ "Geek Trivia: A leap of fakes". 14 September 2004. Retrieved 18 August 2016.
- ^ "Gagarin's Falsified Flight Record". Seeker. 12 April 2012. Retrieved 7 July 2022.
- ^ "The Discovery of Eris". Space Daily. 2 March 2007. Retrieved 6 June 2015.
- ^ "Object Bigger than Pluto Discovered, Called 10th Planet". Space.com. 29 July 2005. Retrieved 6 June 2015.
- ^ "Pluto and the Developing Landscape of Our Solar System". International Astronomical Union. Retrieved 6 June 2015.
- ^ "Planet community in a spin". ABC. 25 August 2006. Retrieved 6 June 2015.
- ^ "Big Gulp: Flaring Galaxy Marks the Messy Demise of a Star in a Supermassive Black Hole" Scientific American
- ^ "Scientists discover water-rich asteroid orbiting dead star GD 61 outside our solar system". Pentagonpost.com. Archived from the original on 2013-10-13. Retrieved 2013-10-12.
- ^ "Watery asteroid discovered in dying star points to habitable exoplanets". Phys.org. Retrieved 2013-10-12.
- ^ Mack, Eric (2011-10-17). "Newly spotted wet asteroids point to far-flung Earth-like planets | Crave - CNET". News.cnet.com. Retrieved 2013-10-12.
- S2CID 182916902. Retrieved 2016-02-11.
- ^ Landau, Elizabeth; Chou, Felicia; Washington, Dewayne; Porter, Molly (16 October 2017). "NASA Missions Catch First Light from a Gravitational-Wave Event". NASA. Retrieved 17 October 2017.
- S2CID 217180814.
- ^ "Event Horizon Telescope". eventhorizontelescope.org. Retrieved 2019-04-11.
- ^ "Virginia Student Earns Honor of Naming NASA's Next Mars Rover". NASA. 5 March 2020. Retrieved 30 March 2020.
- ^ "Alabama High School Student Names NASA's Mars Helicopter". NASA’s Mars Exploration Program. Retrieved 20 February 2021.
- A. Baker and L. Chapter (2002), "Part 4: The Sciences". In M. M. Sharif, "A History of Muslim Philosophy", Philosophia Islamica.
- Ahmad Dallal, "Science, Medicine and Technology.", in The Oxford History of Islam, ed. John Esposito, New York: Oxford University Press, (1999).
- Asghar Qadir (1989). Relativity: An Introduction to the Special Theory. World Scientific, ISBN 9971-5-0612-2.
- George Saliba (1999). Whose Science is Arabic Science in Renaissance Europe? Columbia University.