Helios Helium
Above is an image of the relatively quiet Sun
made on May 18 in light emitted
by ionized
Helium atoms in
the Solar chromosphere.
Helium was first discovered in
the Sun in 1868,
its name fittingly derived from from the Greek word Helios, meaning
Sun. Credit for the discovery goes to astronomer Joseph Lockyer.
Lockyer relied on a recently developed
technique of spectroscopy,
dissecting sunlight into a spectrum,
and the idea that each element produces a characteristic spectral pattern
of bright lines.
He noticed a yellow line in a solar spectrum made during an eclipse
which could not be accounted for by elements known on Earth. Almost 27
years later
Helium was finally discovered on Earth when the
spectrum of a
Helium bearing mineral of Uranium
provided an exact match to the
previously detected element of
the Sun. Helium is now known to be
the second most abundant element (after Hydrogen) in the Universe.