Levels of the gas xenon in the Earth's atmosphere are way lower—to the tune of 90%—than scientists believe they should be, prompting a mystery one calls "the missing xenon paradox." While some believe the gas escaped into space, many have argued it's in the Earth's core—and new research suggests the latter group is right, LiveScience reports. Their assessment involved a new look at findings from 1997 that found xenon wouldn't react with iron, which makes up a large part of the core.
The earlier experiments, however, dealt with far lower pressures than those found in Earth's inner core, says study author Yanming Ma. His team found that the elements at the core, iron and nickel, could in fact react with xenon—and the core may be where all that "missing" gas is, LiveScience notes. "We do hope future high-pressure experiments can be carried out to confirm our predictions," says Ma.