When and Where Was Helium Discovered? Key Facts
Helium was first detected on the Sun in 1868 by French astronomer Pierre Janssen and English astronomer Norman Lockyer. Janssen observed a bright yellow line in the solar spectrum during an eclipse in India, and Lockyer confirmed it was a new element, naming it after the Greek sun god Helios. The element was not found on Earth until 1895, when Scottish chemist William Ramsay isolated it from the uranium mineral cleveite.
The Discovery in Detail
The story starts with the Sun. During an eclipse on August 18, 1868, Janssen used a spectroscope to examine sunlight and noticed a spectral line at 587.49 nanometers that did not match any known element Royal Society of Chemistry. Lockyer, working independently in England, concluded the line came from an unknown substance and proposed the name helium. For decades, scientists thought helium existed only in the Sun’s atmosphere.
That changed in 1895. Ramsay was studying the gas released when cleveite was treated with acid. He collected the gas and sent samples to Lockyer and William Crookes, who confirmed the spectral line matched the one seen in sunlight Encyclopædia Britannica. Ramsay had found terrestrial helium. Later that year, Swedish chemists Per Cleve and Nils Langlet independently isolated helium from the same mineral.
A quick example of how helium’s discovery relates to its properties: the element’s low density and non-reactivity made it ideal for balloons and airships. The first helium-filled balloon flew in 1921, and by the 1930s, helium was used in U.S. Navy blimps because it would not burn like hydrogen.
Key Takeaways
- Helium was first discovered on the Sun in 1868 by Janssen and Lockyer, making it the only element initially found outside Earth.
- The element was isolated on Earth in 1895 by William Ramsay from the mineral cleveite.
- Helium’s name comes from the Greek “Helios,” meaning sun, reflecting its solar origin.
- Helium is the second lightest element and the second most abundant in the universe, but it is rare on Earth and mostly comes from natural gas deposits.
