Celebrating 22 Years on the Web
Find science on or your birthday


Stories About Chemistry


80. Chemical Analysis of... the Sun

In anticipation of the solar eclipse of 1868 astronomers, as always, prepared a great deal of equipment. This time the list included a spectroscope, the instrument which had not long before enabled the discovery of several new elements.

The eclipse passed, and everything settled back to normal. But on July 25, 1868, the French Academy of Science received two letters simultaneously, one from the shores of distant India from the Frenchman Janssen, and the other from England, from the Englishman Lockyer. The contents of both letters were the same almost word for word: each of the authors informed the Academy that he had, by means of spectrum analysis, discovered an element on the Sun that was unknown on Earth. It gave a yellow line in the spectrum, resembling the sodium line in colour. But this line had nothing to do with sodium.

The esteemed assembly of scientists was greatly astonished. Janssen and Lockyer had not only succeeded in “analysing” the Sun, but were claiming to have discovered a new element as well!

On Earth helium (such was the name given to the “solar element”) was discovered only 27 years later, in 1895.

In honour of this great event, the discovery of a method which made possible investigation of the secrets of the distant cosmic bodies, the French Academy passed a decision to coin a special medal. The method was indeed worth a special medal. By any other method at least a very small amount of substance must be available to perform the analysis with. Spectrum analysis defies all distances.

After the discovery of the “solar element” scientists more than once trained their spectrographs (recording spectroscopes) on the Sun, and it meekly told them all about itself.

After the Sun came the turn of other stars, near and distant. The glitter of stellar atmospheres reached the spectroscopes on Earth and in the silence of their laboratories scientists studied the intricate palisade of all kinds of spectral lines. In the heavenly bodies scientists found the elements that were already known on Earth.

Only eighty years later did solar helium pass on the relay of scientific surprises to the element technetium, the one that occupied box 43 in the Mendeleyev Table. A ghost in terrestrial ores, technetium was first discovered in the spectra of certain stars, and only after that were traces of the element found on Earth. In the stars technetium is by no means a rare element. It forms in them continuously as a result of nuclear reactions.

No more new elements were discovered on the Sun or in any of the stars, and probably never will be. The universe is uniform: the Earth, the Sun, the planets and stars and all the heavenly bodies in general consist of the same chemical elements.

But the curious thing is that the “balance” of chemical elements in the skies is different from what it is on Earth. Not oxygen and silicon predominate in outer space, but hydrogen and helium. The amount of these first two representatives of the Periodic System in the universe is many times greater than that of all the rest of the elements taken together. See what a surprising paradox stellar chemistry brings us: our galaxy is primarily a kingdom of hydrogen.

< back     next >

- 100 -
Sophie Germain
Gertrude Elion
Ernest Rutherford
James Chadwick
Marcel Proust
William Harvey
Johann Goethe
John Keynes
Carl Gauss
Paul Feyerabend
- 90 -
Antoine Lavoisier
Lise Meitner
Charles Babbage
Ibn Khaldun
Ralph Emerson
Robert Bunsen
Frederick Banting
Andre Ampere
Winston Churchill
- 80 -
John Locke
Bronislaw Malinowski
Thomas Huxley
Alessandro Volta
Erwin Schrodinger
Wilhelm Roentgen
Louis Pasteur
Bertrand Russell
Jean Lamarck
- 70 -
Samuel Morse
John Wheeler
Nicolaus Copernicus
Robert Fulton
Pierre Laplace
Humphry Davy
Thomas Edison
Lord Kelvin
Theodore Roosevelt
Carolus Linnaeus
- 60 -
Francis Galton
Linus Pauling
Immanuel Kant
Martin Fischer
Robert Boyle
Karl Popper
Paul Dirac
James Watson
William Shakespeare
- 50 -
Stephen Hawking
Niels Bohr
Nikola Tesla
Rachel Carson
Max Planck
Henry Adams
Richard Dawkins
Werner Heisenberg
Alfred Wegener
John Dalton
- 40 -
Pierre Fermat
Edward Wilson
Johannes Kepler
Gustave Eiffel
Giordano Bruno
JJ Thomson
Thomas Kuhn
Leonardo DaVinci
David Hume
- 30 -
Andreas Vesalius
Rudolf Virchow
Richard Feynman
James Hutton
Alexander Fleming
Emile Durkheim
Benjamin Franklin
Robert Oppenheimer
Robert Hooke
Charles Kettering
- 20 -
Carl Sagan
James Maxwell
Marie Curie
Rene Descartes
Francis Crick
Michael Faraday
Srinivasa Ramanujan
Francis Bacon
Galileo Galilei
- 10 -
John Watson
Rosalind Franklin
Michio Kaku
Isaac Asimov
Charles Darwin
Sigmund Freud
Albert Einstein
Florence Nightingale
Isaac Newton

by Ian Ellis
who invites your feedback
Thank you for sharing.
Today in Science History
Sign up for Newsletter
with quiz, quotes and more.