The discovery of helium actually occurred in various phases over a period of roughly forty years. That is, although it was detected and subsequently named, its existence was very much open for debate throughout its early history. It wasn’t absolutely understood until the advent of quantum physics.

It was first detected through a devise known as a spectrometer during the Indian solar eclipse of August 18, 1868. Upon viewing the spectrum of the suns “prominences” during the eclipse, various spectral lines were seen by several astronomers, one of which was a new prominent line in the yellow region of the spectrum that had never been seen before. Although this was the first detection of what later became known as helium, no scientist during this eclipse thought they had discovered a new element. The name “helium”, coined by Norman Lockyer, did not appear until 1871. Nevertheless, this yellow line had only been seen on the sun and could not be found anywhere on earth.

It took 27 years before helium was actually discovered terrestrially by William Ramsay, an English chemist. Ramsay, when studying the spectra of gases released when treating a uranium-based mineral, immediately saw the yellow line that had been seen on the sun. On March 27, 1895, the discovery of the yellow “helium” line on Earth was revealed to the public at the annual meeting of the Chemical Society in London. Although this was a significant discovery, there was still doubt for many years if this yellow line was a unique element or rather a “mixture” of two or more gases.

Just before the turn of the century, Ernest Rutherford and Frederick Soddy discovered that helium was actually a product of the radioactive decay of the heavy elements, Uranium and Thorium.

Nearly all of the helium found in the earth today comes from this radioactive decay of uranium and thorium-rich minerals. As these heavy elements decay, various forms of particles are emitted such as alpha, beta, and gamma radiation. An alpha particle, which is nothing more than a helium nucleus (two protons and two neutrons), will then pick up two electrons to form the helium atom. Millions of years are required to form any substantial amount of commercial helium in natural gas.