In real life krypton is a noble gas which is commonly used in neon signs and laser light shows, says Allan Blackman from AUT in ep 42 of Elemental.

The make-believe planet of Krypton is well-known in popular culture as Superman's home planet. But in real life krypton is an element on the periodic table.

Its name comes from the Greek word kryptos, meaning hidden.

Krypton, chemical symbol Kr and atomic number 36 - is a mostly unreactive noble gas, discovered in 1898 by William Ramsay, who also found helium and argon.

Between 1960 and 1983, krypton was the basis for the definition of the metre.

During the Cold War, levels of the radioactive Kr 85 isotope in the atmosphere indicated how much nuclear material was being produced possible use as weapons from nuclear reactors and nucelar fuel reprocessing plants.

Red 'neon' lights and high-powered red laser lights often use krypton, says Professor Allan Blackman from AUT.

Go to this episode on rnz.co.nz for more details