World running out of helium
It is the second-lightest element in the universe, has the lowest boiling point of any gas and is commonly used to inflate party balloons.
But helium is also a non-renewable resource and the world's reserves are about to run out.
Scientists have warned that the gas is being depleted at an astonishing rate because of a law passed in the United States in 1996 which has effectively made helium too cheap to recycle.
Experts warn that the world could run out of helium within 25 to 30 years,