150 years ago today, the colorless, odorless, non-toxic gas, Helium, was first discovered. Named for the Greek Titan of the Sun, Helios, it showed up as an unknown yellow spectral line signature during a solar eclipse.
Norman Lockyer was the first to propose that it was a new element, which he named. The second most abundant element in the observable universe, most helium in the universe is helium-4, the vast majority of which was formed during the Big Bang. Used in the cooling of superconducting magnets, in MRI scanners, and for arc welding, a well-known but minor use is as a lifting gas in balloons and airships. (1868)
