The volcanoes of the Tanzanian Rift Valley conceal a huge deposit of helium, enough to delay by many years the date when humanity has to confront a shortage of the precious gas. The news will be a relief to scientists who rely on helium's cooling powers and doctors dependent on the same properties to make MRI machines operate.
Helium is the second most common element in the universe. However, it is so light and nonreactive, we have long lost to space all the helium that formed with Earth. We can use it to make balloons or funny voices because new supplies are formed by radioactive decay deep underground and trapped in caverns of rock.
However, we are using helium far faster than it is being created, leading to fears that supplies will soon run out. Liquid helium is almost irreplaceable as a cooling mechanism for medical and scientific equipment, capable of reaching temperatures far below those that can be achieved with current practical alternatives.
Unless we can scoop helium from the atmosphere of Jupiter, whose enormous gravity keeps its helium from escaping, we must eventually face a reckoning. Nevertheless, that danger is now further off than some have feared, with the announcement at the Goldschmidt Conference in Japan of a major deposit of helium beneath Tanzania.