Helium was discovered in the Sun before it was identified on Earth.
In 1868, astronomers examining a solar eclipse observed an unknown yellow spectral line. They concluded that the line belonged to a previously unknown element and named it helium after Helios, the Greek Sun god. Helium was later isolated on Earth in 1895 by William Ramsay from the uranium mineral cleveite.
Helium has atomic number 2 and is the second-lightest element. It is a noble gas, so its atoms have a complete outer electron shell and are exceptionally unreactive. Helium is also nonflammable, unlike hydrogen, making it useful in balloons and airships.
A frequent mix-up is assuming helium was first discovered in a terrestrial mineral. Its first recognized evidence came from solar spectroscopy, while its terrestrial isolation happened decades later.