Who cares?Most people reading the title probably thought exactly that.Helium? And what's that three mean? And so what if we're running out of it? Bear with me and I'll try to change your mind.Helium-3 is an uncommon isotope of Helium that has two protons and a single neutron. It occurs naturally and can be produced through the beta decay of tritium, an isotope of hydrogen with three protons.