Helium was first discovered in the Sun. French astronomer Pierre Janssen in 1868 found proof that a new element existed in the Sun. He called the element helium. Helium was isolated by Sir William Ramsay and independently by N. A. Langley and P. T. Cleve at 1895 in London, England and Uppsala, Sweden.
There are two isotopes of Helium, 3He, and 4He.
Helium-4, the most common isotope is produced on Earth.
Helium-3 is present on Earth only in trace amounts.