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18/08/1868 French astronomer Pierre Janssen discovers helium

While observing the solar eclipse at Guntur, Madras State, British India, he noticed bright lines in the spectrum of the chromosphere, showing that the chromosphere is gaseous. This was the first observation of this particular spectral line, and one possible source for it was an element not yet discovered on the earth.


  • Essentials 

  • Pierre Janssen 

  • Life, work, and interests 

  • Discovery of helium 

  • Observatories 

  • International Meridian Conference 

  • Death, honors, and legacy