Widely used to fill balloons because it is lighter than air, did you know helium gets its name from the Greek word Helios, meaning ‘Sun’? There’s an unusual story behind its discovery. Unlike most elements, helium was first identified not on Earth, but in the Sun’s atmosphere.
In 1868, French astronomer Pierre Janssen travelled to India to observe a total solar eclipse. On 18 August, while observing the eclipse at Guntur in the present-day Andhra Pradesh, he noticed a bright yellow line in the Sun’s spectrum that did not correspond to any known element.
English astronomer Sir Norman Lockyer independently observed the same unusual yellow line later that year, on 20 October, while studying the solar spectrum. He concluded that it belonged to an element that had not yet been discovered on Earth. Along with chemist Edward Frankland, he suggested the name helium, after Helios, the Greek Sun god. Helium is used to cool the powerful magnets in MRI scanners, detect leaks in industrial equipment, protect materials during welding, and help pressurize fuel systems in spacecraft. Its low boiling point also makes liquid helium valuable in scientific research.
