Getting a reaction from helium

Helium is usually considered to be one of the most inert of elements, reacting with nothing. However, a new theoretical study backed up with data from diamond anvil experiments suggest that under sufficient pressure this otherwise unresponsive element can form an electride with sodium, Na2He and there are hints that it might even form an oxygen-containing analog at lower pressure. Such materials have implications for understanding the evolution of stars and gas giant planets that contain vast quantities of helium and other elements under huge pressures. It might also point to a mechanism by which earth's helium may not all be lost to space.