Quick Index
Solar Eclipses | Lunar Eclipses | Blog | Night Sky | Upcoming Eclipses | Photo Index | Travel | Potpourri | Links | Store | Picks | Search
2159 to 1948 B.C.
Legendary dates from China in the Shu Ching of the first recorded solar eclipse. In this myth, Chinese astronomers Hsi and Ho fail to prevent or predict or properly react to an eclipse and are ordered to be executed by an angry emperor
1307 B.C.
First recorded observation of the corona (or prominences?) during a solar eclipse--in China on oracle bones: "three flames ate up the Sun, and a great star was visible"
1223 B.C., March 5
Oldest record of a verifiable solar eclipse--on a clay tablet in the ruins of Ugarit (Syria)
1217 B.C.
Oldest Chinese record of a verifiable solar eclipse--inscriptions on an oracle bone by the Shang people
585 B.C., May 28
A total eclipse in the midst of a battle between the Lydians and Medes scares both sides; hostilities are suspended, according to the Greek historian Herodotus (several other dates are possible)
6th century B.C.
Babylonians (Chaldeans) are said to be able to predict eclipses of the Sun and Moon, supposedly based on cycles such as the saros, but more likely from the positions of the Moon's nodes
450 B.C.?
Anaxagoras (Greece) is probably Greek philosopher Anaxagoras proposesthe first to realize that the Moon is illuminated by the Sun, thus providing a scientific explanation for eclipses
431 B.C., August 3
Oldest European record of a verifiable solar eclipse (annular)--by the Greek historian Thucydides
130 B.C.
Greek astronomer Hipparchus uses the position of the Moon's shadow during a solar eclipse to estimate the distance to the Moon (accurate to about 13%)
20 B.C.?
Liu Hsiang first in China to explain that the Moon's motion hides the Sun to cause solar eclipses
150 A.D.?
Ptolemy (Alexandria) demonstrates the computation of solar and lunar eclipses based on their apparent motions rather than the periodic repetition of eclipses
334 July 17
Firmicus (Sicily) is first to report solar prominences, seen during an annular eclipse
418 July 19
First report of a comet discovered during a solar eclipse, seen by the historian Philostorgius in Asia Minor
9th century
Shadow bands during a total eclipse are described for the first time--in the Volospa, part of the old German poetic edda
968 December 22
First clear description of the corona seen during a total eclipse--by a chronicler in Constantinople
1605
Johannes Kepler (Germany) is the first to comment scientifically on the solar corona, suggesting that it is light reflected from matter around the Sun (based on reports of eclipses; he never saw a total eclipse)
1683
Gian Domenico Cassini (Italy/France) explains zodiacal light as sunlight reflected from small solid particles in the plane of the solar system
1687
Isaac Newton (England) publishes his Principia, including the law of universal gravitation, which makes precise long-range eclipse prediction possible
1695
Edmond Halley (England) is first to notice that the reported times and places of ancient eclipses do not correlate with calculations backward from his era; he concludes correctly that the Moon's orbit has changed slightly (secular acceleration)
1706 May 12
An English ship captain named Stannyan, on vacation in Switzerland, reports a reddish streak (chromosphere? prominence?) along the rim of the Sun as the eclipse becomes total
1715 May 3
Edmond Halley (England), during an eclipse in England, is the first to report the phenomenon later known as Baily's Beads; also notes bright red prominences and the east-west asymmetry in the corona, which he attributes to an atmosphere on the Moon or Sun
1715
Gian Domenico Cassini (Italy/France) proposes that the light responsible for the corona also causes the zodiacal light
1724 May 22
Giacomo Filippo Maraldi (Italy/France) concludes that the corona is part of the Sun because the Moon traverses the corona during an eclipse
1733 May 13
Birger Wassenius (Sweden), observing an eclipse near G�teborg, is the first to report prominences visible to the unaided eye; he attributes them to the Moon
1749
Richard Dunthorne (United Kingdom) calculates the approximate secular acceleration of the Moon based on Halley's 1693 findings
1795
William Herschel (United Kingdom) proposes that sunspots are holes in the Sun's hot clouds through which the dark, cool, solid surface of the Sun can be seen; he also suggests that this surface may be inhabited
1800
William Herschel (United Kingdom) founds science of solar physics by measuring the temperature of various colors in the Sun's spectrum; he detects infrared radiation beyond the visible spectrum
1801
Johann Wilhelm Ritter (Germany), following the lead of Herschel, uses the spectrum of the Sun to establish the existence of ultraviolet radiation
1802
Dark (absorption) lines are discovered in the Sun's spectrum by William Wollaston (United Kingdom)
1806 June 16
José Joaquin de Ferrer (Spain), observing at Kinderhook, New York, gives the name corona to the glow of the faint outer atmosphere of the Sun seen during a total eclipse; he proposes that the corona must belong to the Sun, not the Moon, because of its great size
1820
Carl Wolfgang Benjamin Goldschmidt (Germany) calls attention to the shadow bands visible just before and after totality at some eclipses (based on the eclipse of November 19, 1816?)
1833
David Brewster (United Kingdom) shows that some of the dark lines in the Sun's spectrum are due to absorption in the Earth's atmosphere, but most are intrinsic to the Sun
1836 May 15
Francis Baily (United Kingdom), during an annular eclipse in Scotland, calls attention to the brief bright beads of light that appear close to totality as the Sun's disk is blocked except for sunlight streaming through lunar valleys along the limb. This phenomenon becomes known as Baily's Beads
1842 July 8
Francis Baily (United Kingdom), at an eclipse in Italy, focuses attention on the corona and prominences and identifies them as part of the Sun's atmosphere
1845
First clear photograph of the Sun: a daguerreotype by Hippolyte Fizeau and Léon Foucault (France)
1848
Julius Robert Mayer (Germany) shows through calculations that the Sun cannot shine a significant length of time by ordinary chemical burning; he incorrectly attributes the energy of the Sun to the heat released by the impact of meteoroids on the Sun
1851 July 28
First astronomical photograph of a total eclipse: a daguerreotype by Berkowski at K�nigsberg, Prussia
1851 July 28
Robert Grant and William Swan (United Kingdom) and Karl Ludwig von Littrow (Austria) determine that prominences are part of the Sun because the Moon is seen to cover and uncover them as it moves in front of the Sun
1851 July 28
George B. Airy (United Kingdom) is the first to describe the Sun's chromosphere: he calls it the sierra, thinking that he is seeing mountains on the Sun, but he is actually seeing small prominences (spicules) that give the chromosphere a jagged appearance. Because of its reddish color, J. Norman Lockyer names this layer of the Sun's atmosphere the chromosphere in 1868
1852
Edward Sabine (Ireland/United Kingdom), Johann Rudolf Wolf (Germany), and Alfrede Gautier (France) independently link the sunspot cycle to magnetic fluctuations on Earth; the study of solar-terrestrial relationships begins
1854
Hermann von Helmholtz (Germany) attributes the energy of the Sun to heat from gravitational contraction
1858
Richard C. Carrington (United Kingdom), studying sunspots, identifies the Sun's axis of rotation and discovers that the Sun's rotational period varies with latitude. He also discovers that the latitude of sunspots migrates toward the equator during the course of a sunspot cycle
1859 September 1
Richard C. Carrington and R. Hodgson (United Kingdom) are the first to observe a flare on the Sun. They both also note that a magnetic storm in progress on Earth intensifies soon afterwards, but they refrain from connecting the two events
1859
Gustav Kirchhoff (Germany) uses spectroscopy to show that the surface of Sun cannot be solid and that the Sun's atmosphere (which he identifies with the corona) is responsible for the dark lines in the Sun's spectrum
1860 July 18
First wet plate photographs of an eclipse; they require 1/30 of the exposure time of a daguerreotype
1860 July 18
Warren De La Rue (United Kingdom) and Angelo Secchi (Italy) use photography during a solar eclipse in Spain to demonstrate that prominences (and hence at least that region of the corona) are part of the Sun, not light scattered by the Earth's atmosphere or the edge of the Moon, because the corona looks the same from sites 250 miles apart
1861-62
Gustav Kirchhoff (Germany) maps the solar spectrum
1868 August 18
During an eclipse seen from the Red Sea through India to Malaysia and New Guinea, prominences are first studied with spectroscopes and shown to be composed primarily of hydrogen by James Francis Tennant (United Kingdom), John Herschel (United Kingdom--son of John F. W. Herschel, grandson of William), Jules Janssen (France), Georges Rayet (France) and Norman Pogson (United Kingdom/India)
1868
Pierre Jules C�sar Janssen (France) and J. Norman Lockyer (United Kingdom) independently demonstrate that prominences are part of the Sun (not Moon) by observing them in days after the eclipse of August 18
1868
J. Norman Lockyer (United Kingdom) identifies a yellow spectral line in the Sun's corona as the signature of a chemical element as yet unknown on Earth. He later names it helium, after the Greek word helios, the Sun. Helium is first identified on Earth by William Ramsay in 1895
1869 August 7
Charles Augustus Young and William Harkness (United States) independently discover a new bright (emission) line in the spectrum of the Sun's corona, never before observed on Earth; they ascribe it to a new element and it is named coronium. In 1941, this green line is identified by Bengt Edlén (Sweden) as iron that has lost 13 electrons
1869
Thomas Andrews (Ireland) shows more conclusively than those before him that the Sun must be made essentially of hot gas
1870 December 2
Jules Janssen (France) uses a balloon to escape the German siege of Paris in order to study the December 22 eclipse in Algeria. He reaches Algeria, but the eclipse is clouded out
1870 December 22
Charles A. Young (United States), observing an eclipse in Spain, discovers that the chromosphere is the layer in the solar atmosphere that produces the dark lines in the Sun's spectrum
1871 December 12
Jules Janssen (France) uses spectroscopy from an eclipse in India to propose that the corona consists of both hot gases and cooler particles and hence is part of the Sun
1874
Samuel P. Langley (United States) proposes that the bright granules in the Sun's photosphere are columns of hot gas rising from the interior and the dark interstices are cooler gases descending; he also proposes that the bright granules are responsible for almost all of the Sun's light
1871/1878
Jules Janssen (France) notices that the shape of the corona changes with the sunspot cycle. At sunspot maximum, the corona is rounder (1871); at sunspot minimum, the corona is more equatorial (1878). This discovery is the most convincing evidence that the corona is part of the Sun
1878 July 29
Height of search for intra-Mercurial planet Vulcan using eclipses to block the Sun. Several observers claim sightings, but they were never confirmed. The problem is finally resolved by Einstein in his general theory of relativity in 1916
1878 July 29
Samuel P. Langley and Cleveland Abbe (United States), observing from Pike's Peak in Colorado, and Simon Newcomb (United States), observing from Wyoming, notice coronal streamers extending more than 6 degrees from the Sun along the ecliptic and suggest that this glow is the origin of the zodiacal light
1884
Marie Alfred Cornu (France) applies Langley's work using the Doppler Effect of the Sun's rotation to distinguish between dark (absorption) lines created in the Sun's atmosphere and those created in the Earth's atmosphere
1887
Theodor von Oppolzer's (Czechoslavakia) monumental Canon ofEclipses published, giving details of almost all solar and lunar eclipses from 1207 B.C. to 2161 A.D.
1887 August 19
Dmitry Ivanovich Mendeleev (Russia) uses a balloon to ascend above the cloud cover to an altitude of 11,500 feet (3.5 kilometers) to observe an eclipse in Russia
1893 & 1894
George Ellery Hale (United States) and Henri Deslandres independently develop spectroheliographs to photograph the Sun's chromosphere, prominences, and flares without waiting for eclipses
1894
William E. Wilson and P. L. Gray (Ireland) are the first to measure with reasonable accuracy the effective temperature of the Sun's photosphere: 11,200°F (6,200°C), about 800°F (400°C) too high
1899
Friedrich Ginzel (Austria), Oppolzer's co-worker, uses data from the Canon of Eclipses for his Special Canon of Solar and LunarEclipses, which lists references in classical literature to eclipses between 900 B.C. and 600 A.D.
1908
George Ellery Hale (United States) shows that sunspots are regions with strong magnetic fields
1911
Albert Einstein (Germany), working on his general theory of relativity, proposes that gravity bends light and that this phenomenon might be observed during a solar eclipse
1916
Einstein publishes his complete general theory of relativity with a revised prediction for the gravitational deflection of starlight
1919 May 29
Arthur S. Eddington (United Kingdom) and co-workers, observing a total solar eclipse from Principe and Brazil, confirm the bending of starlight by gravity as predicted by Einstein in his general theory of relativity
1922 September 21
William Wallace Campbell and Robert J. Trumpler (United States) reconfirm Einstein's relativistic bending of starlight during an eclipse in Wallal, Australia
1930
Bernard Lyot (France) invents the coronagraph, which creates an artificial eclipse inside a telescope so that the corona can be studied outside of eclipses
1932 August 31
G. G. Cillié (United Kingdom) and Donald H. Menzel (United States) use eclipse spectra to show that the Sun's corona has a higher temperature (faster atomic motion) than the photosphere. Confirmed, with much higher temperatures, by R. O. Redman during an eclipse in South Africa on October 1, 1940
1952
Discovery of strong absorption lines of the molecule carbon monoxide in the solar infrared spectrum by Leo Goldberg and colleagues (United States)
1958
Eugene Parker (United States) provides a theoretical model for the solar wind by showing that the corona must be expanding and by demonstrating how to calculate flow speeds and densities
1959
Robert Leighton, Robert Noyes, and George Simon (United States) discover 5-minute oscillations of the surface of the Sun, leading to the birth of helioseismology and the "acoustic" exploration of the Sun's interior
1961
Marcia Neugebauer and her coworkers (United States) use NASA's Mariner 2 spacecraft to confirm major features of Eugene Parker's 1958 model of the solar wind
1962-1972
NASA's Orbiting Solar Observatories (OSOs)
1968-present
Raymond Davis (United States) measures the flux of solar neutrinos and discovers that it is only a fraction (about 1/3) of the predicted flux from expected nuclear reactions in the core of the Sun
1971
John Belcher and Leverett Davis (with earlier help from Ed Smith) (United States) demonstrate that the solar wind is full of Alfvén waves, stimulating the study of coronal heating and solar wind acceleration by waves
1972
Using data from an Orbiting Solar Observatory (OSO 4), Richard H. Munro and George L. Withbroe (United States) discover coronal holes, later shown by Werner M. Neupert and Victor Pizzo (United States) to be the source of solar wind because they correlate with magnetic storms on Earth
1972
Robert Noyes (United States) and Donald Hall (Australia) recognize that the carbon monoxide molecules on the Sun (discovered 1952) must be colder than the gases around them, with a temperature significantly below the minimum temperature measured by other techniques
1973 June 30
John Beckman (United Kingdom) and other scientists use a Concorde supersonic passenger jet flying at 1,250 miles per hour (2,000 kilometers per hour) over Africa to extend the duration of solar eclipse totality to 74 minutes--10 times longer than can ever be observed from the ground
1973-1974
Astronauts on NASA's Skylab orbiting laboratory study corona over a nine-month period using the Apollo Telescope Mount: (1) x-ray images show coronal holes and the relationship between these "open-field" regions with the mysterious "M-regions" postulated by Sydney Chapman and Julius Bartels (Germany) in 1940 but never seen; (2) the high-speed solar wind escaping from coronal holes produces geomagnetic disturbances when it reaches the Earth about two days after the coronal hole passes through the central meridian of the Sun; (3) the active corona is composed of loops of plasma following strong magnetic field lines, indicating that magnetism heats the corona
1973-1978
Michael Schulz (United States) begins a shift from thinking about the Sun as being magnetically sectored north-south to thinking of the sectors essentially following the solar equatorial plane. Ed Smith and co-workers confirm this discovery by using the NASA spaceprobe Pioneer 11 (1978) to observe the Sun at high solar latitudes. The magnetic sectors form a "ballerina skirt" fluttering around the Sun's equatorial plane
1979 February 26
Alan Clark (United Kingdom/Canada) and Rita Boreiko (Canada) begin airborne infrared observations during eclipses (through 1988)
1981-1988
Airborne far infrared observations during eclipses by Eric Becklin, Charles Lindsey, and colleagues (United States) demonstrate a significant limb extension and smaller-than-predicted limb brightening of the Sun at wavelengths between 20 and 800 micrometers
1987
Eugene Parker (United States) proposes that the coronal magnetic field must be continuously reconnecting and releasing energy and that this mechanism can heat the corona
1988
Joseph Hollweg and Walter Johnson (United States) present a model of coronal holes in which high-frequency ion-cyclotron waves heat the corona and that the resulting fast solar wind is driven by hot protons. Although data at the time indicate that the protons are not hot, later SOHO data (John Kohl, 1995) show that the protons are hot, as predicted
1990 October
ESA/NASA Ulysses spacecraft launched from Space Shuttle into polar orbit around the Sun (via gravitational assist from Jupiter) to explore the polar regions of the Sun and its corona, which are poorly seen from Earth
1991 July 11
Astronomers observe the total eclipse from the world's largest optical observatory, Mauna Kea on Hawaii, with the 15-meter James Cleark Maxwell Telescope (United Kingdom-Netherlands-Canada), the 4-meter Canada-France-Hawaii Telescope, the 3-meter Infrared Telescope Facility (NASA), and the University of Hawaii's 2-meter telescope, making sensitive radio and infrared measurements of the solar chromosphere and obtaining high-resolution optical images of the corona and prominences
1994 May 10
Alan Clark (United Kingdom/Canada) and coworkers use lunar limb occultation during an annular eclipse to measure profiles of spectral lines in the chromosphere formed by carbon monoxide
1998 April 1
NASA TRACE (Transition Region and Coronal Explorer) satellite launched; Alan Title and Leon Golub (United States) use TRACE to provide the first daily high-resolution observations of the Sun from space
All rights reserved. This material may not be reproduced, published, copied or transmitted in any form, including electronically on the Internet or World Wide Web, without written permission of the authors.
Contact Espenak (at MrEclipse) for more information.
WebMaster: MrEclipse
Last revised: 2008 Jan 22