Helium was discovered in 1868 by French astronomer Jules Janssen (1824-1907).
Along with other scientists, Janssen traveled to India to observe a total eclipse of the Sun on August 18, 1868. The scientists were using a portable spectroscope, technology that had been refined by Janssen and English astronomer Norman Lockyer (1836-1920). They intended to make the first spectroscopic study of the Sun’s corona, and were surprised to see the presence of a bright yellow line in the spectroscope that Janssen attributed to an unknown element. It was Lockyer who called it “Helium”, from the Greek helios, “sun”.
It was not until several years later that Luigi Palmieri (1807-1896), an Italian volcanologist and meteorologist, finally managed for the first time to demonstrate the presence of Helium on Earth, which he detected in 1882 during the spectral analysis of lava from Mt. Vesuvius.
Lastly, on March 26, 1895, Helium was directly observed on Earth when Sir William Ramsay (1852-1916), an English chemist, identified it in uranium ore. Later, Ramsay demonstrated that Helium was produced through the decay of certain heavy nuclei, such as uranium and radium.