Helium is unique among elements because it was first discovered in the Sun, not on Earth. In 1868, during a solar eclipse, French astronomer Jules Janssen and English scientist Norman Lockyer independently observed a yellow spectral line in sunlight that did not match any known element.

Lockyer proposed that this line came from a new, unknown element in the Sun and named it helium, after Helios, the Greek sun god. It wasn’t until 1895 that Sir William Ramsay isolated helium on Earth while studying a mineral called cleveite, confirming its existence terrestrially.

This discovery marked the first time an element was found in space before being found on Earth, showcasing the power of spectroscopy—analyzing light to determine chemical composition—and marking a milestone in both astronomy and chemistry.