On this day in 1868, Pierre Janssen discovered a previously unknown bright yellow line in the spectrum of the chromosphere of the sun during a solar eclipse he was observing from India. This was an indication of a new element. For over 30 years, it was assumed the element was only present in the sun since the spectral line was not observed in the lab until 1895 when Sir William Ramsay examined a gas released from treating the mineral cleveite. Ramsay named the new element “helium” after the greek word helios for the sun. discovered helium in the solar spectrum during eclipse.
203200login-checkAugust 18th
