Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Solar eclipses as an astrophysical laboratory


Observations of the Sun during total eclipses have led to major discoveries, such as the existence of helium (from its spectrum), the high temperature of the corona (though the reason for the high temperature remains controversial), and the role of magnetic fields in injecting energy into—and trapping ionized gases within—stellar atmospheres. A new generation of ground-based eclipse observations reaches spatial, temporal and spectral-resolution domains that are inaccessible from space and therefore complement satellite studies.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Figure 1: The geometry of eclipses.
Figure 2: The corona at totality.
Figure 3: The paths of total eclipses, 2001–25.
Figure 4: The 1 August 2008 eclipse from the ground and from space.
Figure 5: Correcting for the large dynamic range in coronal intensities.


  1. 1

    Golub, L. & Pasachoff, J. Nearest Star: The Surprising Science of Our Sun (Harvard Univ. Press, 2001)

    Google Scholar 

  2. 2

    Held, W. Eclipses: 2005–2017: A Handbook of Solar and Lunar Eclipses and Other Rare Astronomical Events (Floris Books, 2005); transl. from Astronomische Sternstunden (Verlag Freies Geistesleben, 2005)

    Google Scholar 

  3. 3

    Stephenson, F. R. Historical Eclipses and Earth's Rotation (Cambridge Univ. Press, 1997)Shows the value that eclipses have for assessing Earth's rotation over thousands of years.

    Book  Google Scholar 

  4. 4

    Vaquero, J. M. The Sun Recorded Through History: Scientific Data Extracted from Historical Documents (Springer, 2009)

    Book  Google Scholar 

  5. 5

    Guillermier, P. & Koutchmy, S. Total Eclipses: Science, Observations, Myths and Legends (Springer/Praxis, 1999); transl. from Eclipses Totales: Histoire, Découvertes, Observations (Masson, 1998)

    Google Scholar 

  6. 6

    Mauna. Loa Solar Observatory. 〈〉 (2009)

  7. 7

    Pasachoff, J. M. in Astronomy in the Developing World (eds Hearnshaw, J. B. & Martinez, P.) 265–268 (Cambridge Univ. Press, 2007)

    Google Scholar 

  8. 8

    Pasachoff, J. M. in New Trends in Astronomy Teaching (eds Gouguenheim, L., McNally, D. & Percy, J. R.) 202–204 (IAU Colloquium 162, Cambridge Univ. Press, 1998)

    Book  Google Scholar 

  9. 9

    Pasachoff, J. M. Halley and his maps of the total eclipses of 1715 and 1724. Astron. Geophys. 40, 2.18–2.21 (1999)

    Article  Google Scholar 

  10. 10

    Espenak, F. & Meeus, J. Five Millennium Catalog of Solar Eclipses: –1999 to +3000 (2000 BCE to 3000 CE) (Technical Publication TP-2006-214170, NASA, 2008)Provides information about eclipses over an extended period of time, giving both historical and predictive information.

    Google Scholar 

  11. 11

    Cook, A. Halley and the Saros. Q. J. R. Astron. Soc. 37, 349–353 (1996)

    ADS  Google Scholar 

  12. 12

    Williams, S. UK Solar Eclipses from Year 1 (an Anthology of 3,000 Years of Solar Eclipses) (Clock Tower Press, Leighton Buzzard, UK, 1996)

    Google Scholar 

  13. 13

    Espenak, F. & Meeus, J. Five Millennium Canon of Solar Eclipses: –1999 to +3000 (2000 BCE to 3000 CE). (Technical Publication TP-2006-214141, NASA, 2006)

    Google Scholar 

  14. 14

    Littmann, M., Espenak, F. & Willcox, K. Totality: Eclipses of the Sun 3rd edn (Oxford Univ. Press, 2008)

    Google Scholar 

  15. 15

    Mobberley, M. Total Solar Eclipses and How to Observe Them (Springer, 2007)

    Book  Google Scholar 

  16. 16

    Rušin, V. et al. Comparing eclipse observations of the August 1, 2008 solar corona with an MHD model prediction. Trans. Am. Geophys. Un. (Fall Meet.) abstr. SH13B-1524 (2008)

  17. 17

    Rušin, V. in Last Total Solar Eclipse of the Millennium (eds Livingston, W. & Özgüç, A.) 17–31 (ASP Conf. Ser. 205, Astronomical Society of the Pacific, 2000)

    Google Scholar 

  18. 18

    Özkan, M. T. et al. in Modern Solar Facilities—Advanced Solar Science (eds Kneer, F., Puschmann, K. G. & Wittmann, A. D.) 201–204 (Universitätsverlag Göttingen, 2007); 〈〉.

  19. 19

    Zirin, H. Astrophysics of the Sun (Cambridge Univ. Press, 1988)

    Google Scholar 

  20. 20

    Foukal, P. Solar Astrophysics 2nd edn (Wiley-VCH, 2004)

    Book  Google Scholar 

  21. 21

    Aschwanden, M. J. Physics of the Solar Corona: An Introduction with Problems and Solutions 3rd printing (Praxis, 2009).

  22. 22

    Golub, L. & Pasachoff, J. M. The Solar Corona (Cambridge Univ. Press, 1997)Use of not only eclipses but also space observations to provide a survey of current knowledge of our Sun's outer atmosphere.

    Google Scholar 

  23. 23

    Pasachoff, J. M. & Covington, M. The Cambridge Eclipse Photography Guide (Cambridge Univ. Press, 1993)

    Google Scholar 

  24. 24

    Menzel, D. H. A study of the solar chromosphere based upon photographs of the flash spectrum taken by Dr. William Wallace Campbell, Director of the Lick Observatory, at the total eclipses of the Sun in 1898, 1900, 1905 and 1908. Publ. Lick Obs. 17, Part 1 1–303 (1931)

    Google Scholar 

  25. 25

    Meadows, A. J. Early Solar Physics (Pergamon, 1970)

    Google Scholar 

  26. 26

    Pasachoff, J. M., Olson, R. J. M. & Hazen, M. L. The earliest comet photographs: Usherwood, Bond, and Donati 1858. J. Hist. Astron. 27, 129–145 (1996)

    ADS  Article  Google Scholar 

  27. 27

    Rayet, G. A. P. Analyse spectrale des protubérances observées pendant l'éclipse totale visible le 18 aout 1861, à la presqu'ile de Malacca. C.R. Acad. Sci. LXVII, 757–759 (1868)

    Google Scholar 

  28. 28

    Menzel, D. H. & Pasachoff, J. M. On the obliteration of strong Fraunhofer lines by electron scattering in the solar corona. Publ. Astron. Soc. Pacif. 80, 458–461 (1968)

    ADS  Article  Google Scholar 

  29. 29

    Edlén, B. Die Deutung der Emissionslinien im Spektrum der Sonnenkorona. Z. Astrophys. 22, 30–64 (1942)

    ADS  Google Scholar 

  30. 30

    Koutchmy, S., Contesse, L., Viladrich, Vilinga, J. & Bocchialini, K. in The Dynamic Sun: Challenges for Theory and Observations (eds Danesy, D., Poedts, S., de Groof, A. & Andries, J.) 26.1–26.7 (SP-600, ESA, 2005)

    Google Scholar 

  31. 31

    Gabriel, A. H. et al. Rocket observations of the ultraviolet solar spectrum during the total eclipse of 1970 March 7. Astrophys. J. 169, 595–614 (1971)

    ADS  CAS  Article  Google Scholar 

  32. 32

    Kohl, J. L., Gardner, L. D., Strachan, L. & Hassler, D. M. Ultraviolet spectroscopy of the extended solar corona during the SPARTAN 201 mission. Space Sci. Rev. 70, 253–261 (1994)

    ADS  Article  Google Scholar 

  33. 33

    Lang, K. R. The Sun from Space (Springer, 2009)

    Google Scholar 

  34. 34

    Ottewell, G. The Under-Standing of Eclipses (Astronomical Workshop, Greenville, South Carolina, 1991)

    Google Scholar 

  35. 35

    Beckman, J. et al. Eclipse flight of Concorde 001. Nature 246, 72–74 (1973)

    ADS  CAS  Article  Google Scholar 

  36. 36

    Léna, P., Hall, D., Soufflot, A. & Viala, Y. The thermal emission of the dust corona, during the eclipse of June 30, 1973. II — Photometric and spectral observations. Astron. Astrophys. 37, 81–86 (1974)

    ADS  Google Scholar 

  37. 37

    Lindsey, C. et al. Extreme-infrared brightness profile of the solar chromosphere obtained during the total eclipse of 1991. Nature 458, 308–310 (1992)

    ADS  Article  Google Scholar 

  38. 38

    SOHO. pick of the week: Solar eclipse, August 1, 2008. 〈〉 (2008)

  39. 39

    Dyson, F. W., Eddington, A. S. & Davidson, C. A determination of the deflection of light by the Sun's gravitational field from observations made at the total eclipse of May 29, 1919. Phil. Trans. R. Soc. A 220, 291–333 (1920)

    ADS  Article  Google Scholar 

  40. 40

    Crelinsten, J. Einstein's Jury: The Race to Test Relativity (Princeton Univ. Press, 2006)Describes in detail the most famous eclipse in scientific history and its well-known ramifications for testing Einstein's general theory of relativity as well as providing lessons in the philosophy of science.

    MATH  Google Scholar 

  41. 41

    Isaacson, W. Einstein: His Life and Universe (Simon & Schuster, 2007)

    Google Scholar 

  42. 42

    Zirker, J. B. Total Eclipses of the Sun (Princeton Univ. Press, 1995)

    Google Scholar 

  43. 43

    Muhleman, D. O., Ekers, R. D. & Fomalont, E. B. Radio interferometric test of the general relativistic light bending near the sun. Phys. Rev. Lett. 24, 1377–1380 (1970)

    ADS  Article  Google Scholar 

  44. 44

    Shapiro, S. S., Davis, J. L., Lebach, D. E. & Gregory, J. S. Measurement of the solar gravitational deflection of radio waves using geodetic very-long-baseline interferometry data, 1979–1999. Phys. Rev. Lett. 92, 121101 (2004)

    ADS  CAS  Article  Google Scholar 

  45. 45

    Froeschle, M., Mignard, F. & Arenou, F. in Proceedings of the ESA Symposium 'Hipparcos - Venice '97' (eds Perryman, M. A. C., Bernacca, P. L. & Battrick, B.) 49–52 (SP-402, ESA, 1997)

    Google Scholar 

  46. 46

    Bertotti, B., Iess, L. & Tortora, P. A test of general relativity using radio links with the Cassini spacecraft. Nature 524, 374–376 (2003)

    ADS  Article  Google Scholar 

  47. 47

    Evans, D. S. & Winget, K. I. Harlan's Globetrotters: The Story of an Eclipse (Xlibris, Tucson, 2005)

    Google Scholar 

  48. 48

    Texas Mauritanian Eclipse Team. Gravitational deflection of light: Solar eclipse of 30 June 1973, I: Description of procedures and results. Astron. J. 81, 452–454 (1976)

  49. 49

    Van Doorsselaere, T., Nakariakov, V. M. & Verwichte, E. Detection of waves in the solar corona: Kink or Alfvén waves. Astrophys. J. 465, L73–L75 (2008)

    ADS  Article  Google Scholar 

  50. 50

    Klimchuk, J. A. On solving the coronal heating problem. Sol. Phys. 234, 41–77 (2006)

    ADS  Article  Google Scholar 

  51. 51

    Pasachoff, J. M., Babcock, B. A., Russell, K. D. & Seaton, D. B. Short-period waves that heat the corona detected at the 1999 eclipse. Sol. Phys. 207, 241–257 (2002)

    ADS  CAS  Article  Google Scholar 

  52. 52

    Williams, D. R. in SOHO 13—Waves, Oscillations and Small-Scale Transient Events in the Solar Atmosphere: A Joint View from SOHO and TRACE (ed. Lacoste, H.) 513–518 (SP-547, ESA, 2004)Comments on measurements pointed toward distinguishing among theories of coronal heating, the major outstanding coronal research problem.

    Google Scholar 

  53. 53

    Cowsik, R., Singh, J., Saxena, A. K., Srinivasan, R. & Raveendran, A. V. Short-period intensity oscillations in the solar corona observed during the total solar eclipse of 26 February 1998. Sol. Phys. 188, 89–98 (1999)

    ADS  Article  Google Scholar 

  54. 54

    Laffineur, M., Burnichon, M.-L. & Koutchmy, S. Weighted observation of the corona during the total solar eclipse of September 22, 1968. Nature 222, 461–462 (1969)

    ADS  Article  Google Scholar 

  55. 55

    Saito, K. & Tandberg-Hanssen, E. The arch systems, cavities and prominences in the helmet streamer observed at the solar eclipse, November 12, 1966. Sol. Phys. 31, 105–121 (1973)

    ADS  Article  Google Scholar 

  56. 56

    Druckmüller, M., Rušin, V. & Minarovjech, M. A new numerical method of total solar eclipse photography processing. Contrib. Astron. Obs. Skalnaté Pleso 36, 131–148 (2006)

    ADS  Google Scholar 

  57. 57

    Pasachoff, J. M., Rušin, V., Druckmüller, M. & Saniga, M. Fine structures in the white-light solar corona at the 2006 eclipse. Astrophys. J. 665, 824–829 (2007)Shows the state-of-the-art in coronal imaging and points toward the future of computer processing for improving resolution of eclipse observations.

    ADS  Article  Google Scholar 

  58. 58

    Pasachoff, J. M., Kimmel, S. B., Druckmüller, M., Rušin, V. & Saniga, M. The 8 April 2005 eclipse white-light corona. Sol. Phys. 238, 261–270 (2006)

    ADS  Article  Google Scholar 

  59. 59

    Koutchmy, S. in Proc. IAU Symposium 233, Multi-Wavelength Investigations of Solar Activity (eds Stepanov, A. V., Benevolenskaya, E. E. & Kosovichev, A. G.) 509–516 (Cambridge Univ. Press, 2004)

    Google Scholar 

  60. 60

    Koutchmy, S. et al. CFHT eclipse observations of the very fine-scale solar corona. Astron. Astrophys. 281, 249–257 (1994)

    ADS  Google Scholar 

  61. 61

    Kim, I. S. in Last Total Solar Eclipse of the Millennium (eds Livingston, W. & Özgüç, A.) 69–82 (ASP Conf. Ser. 205, Astronomical Society of the Pacific, 2000)

    Google Scholar 

  62. 62

    Chandrasekhar, T., Ashok, N. M., Rao, B. G., Pasachoff, J. M. & Suer, T.-A. in Solar Active Regions and 3D Magnetic Structure 273 (26th Meeting of the IAU, Joint Discussion 3, Cambridge Univ. Press, 2006)

    Google Scholar 

  63. 63

    Noble, M. W. et al. Observing the solar corona with a tunable Fabry-Perot filter. Appl. Opt. 47, 5744–5749 (2008)

    ADS  Article  Google Scholar 

  64. 64

    Pasachoff, J. M. et al. Polar plume brightening during the 29 March 2006 total eclipse. Astrophys. J. 682, 638–643 (2008)

    ADS  Article  Google Scholar 

  65. 65

    Pasachoff, J. M. et al. Coronal observations at the Siberian 2008 total solar eclipse. Bull. Am. Astron. Soc. 41, abstr. 60.03 (2009)

    Google Scholar 

  66. 66

    Ichimoto, K. et al. Measurement of the coronal electron temperature at the total solar eclipse on 1994 November 3. Publ. Astron. Soc. Japan 48, 545–554, plates 15–16 (1996)

    ADS  CAS  Article  Google Scholar 

  67. 67

    Reginald, N. L., St Cyr, O. C., Davila, J. M. & Brosius, J. W. Electron temperature and speed measurements in the low solar corona: Results from the 2001 June eclipse. Astrophys. J. 599, 596–603 (2003)

    ADS  CAS  Article  Google Scholar 

  68. 68

    Reginald, N. L., Davila, J. M. & St Cyr, O. C. Effects of streamers on the shape of the K-coronal spectrum. Sol. Phys. 225, 249–265 (2004)Describes recent use of spectroscopy rather than imaging to study the corona at eclipses.

    ADS  Article  Google Scholar 

  69. 69

    Quémerais, E. & Lamy, P. L. Two-dimensional electron density in the solar corona from inversion of white light images — Application to SOHO/LASCO-C2 observations. Astron. Astrophys. 393, 295–304 (2002)

    ADS  Article  Google Scholar 

  70. 70

    Pang, A. S.-K. Empire and the Sun: Victorian Solar Eclipse Expeditions (Stanford Univ. Press, 2002)

    Google Scholar 

  71. 71

    International Astronomical Union Commission 46 on Education and Development: Program Group on Public Education on the Occasions of Solar Eclipses; Working Group on Solar Eclipses. 〈

  72. 72

    NASA Eclipse Web Site: Solar eclipse page. 〈

  73. 73

    Espenak, F. & Anderson, J. Total Solar Eclipse of 2009 July 22 (TP-2006-214141, NASA, 2006)

    Google Scholar 

  74. 74

    Espenak, F. & Anderson, J. Annular and Total Solar Eclipses of 2010 (TP-2008-214171, NASA, 2008)

    Google Scholar 

  75. 75

    Demircan, O., Selam, S. O. & Albayrak, B. Solar and Stellar Physics through Eclipses (ASP Conf. Ser. 370, Astronomical Society of the Pacific, 2007)

    Google Scholar 

Download references


The author is glad to acknowledge his mentors and eclipse colleagues over the 50-year period that he has been observing his 48 solar eclipses, including D. H. Menzel, J. P. Schierer, B. A. Babcock, S. P. Souza, V. Rušin, M. Druckmüller, M. Saniga and others; L. Golub, R. W. Noyes, E. H. Avrett and H. Zirin for other aspects of solar physics; F. Espenak for eclipse-path calculations; and generations of undergraduate students from Williams College who have participated in expeditions and/or studied eclipse data. At various times, his eclipse research has been supported by the Committee for Research and Exploration of the National Geographic Society, the Astronomy and Atmospheric Sciences Divisions of the National Science Foundation, and the Heliophysics Division of NASA, as well as by Williams College. He thanks M. Brown and the Division of Geological and Planetary Sciences of the California Institute of Technology for hospitality during the writing of this Review. The preparation of the article benefited from NASA's Astrophysical Data System.

Author information



Corresponding author

Correspondence to Jay M. Pasachoff.

PowerPoint slides

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Pasachoff, J. Solar eclipses as an astrophysical laboratory. Nature 459, 789–795 (2009).

Download citation

Further reading


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing