Further evidence of helium on the moon strengthened after a NASA spacecraft detected the element on its surface.
NASA's Lunar Reconnaissance Orbiter (LRO) identified the helium using a spectrometer. The finding adds to the 1972 findings by the Lunar Atmosphere Composition Experiment (LACE) when it detected helium during the Apollo 17's moonwalking mission.
"The question now becomes, does the helium originate from inside the moon - for example, due to radioactive decay in rocks - or from an exterior source, such as the solar wind?" said Southwest Research Institute's Alan Stern, an investigator of the LRO's Lyman Alpha Mapping Project spectrometer (LAMP). "If we find the solar wind is responsible, that will teach us a lot about how the same process works in other airless bodies."
LAMP's purpose is to study the moon's thin atmosphere and believe the helium dates back to more than 50 orbits. According to Stern, LAMP can also identify the source of the helium, if it comes from the moon or perhaps an outside source.
With the LRO, a $540 million Mini Cooper-sized spacecraft, it further assists NASA's plan for future lunar explorations.
LRO has helped discover water on the moon, map the precise topography of the moon's axis, discover Russia's rover Lunokod 1 which vanished back in 1970, and take images of Apollo 11's landing site.
"These ground-breaking measurements were enabled by our flexible operations of LRO as a science mission, so that we can now understand the moon in ways that were not expected when LRO was launched in 2009," said NASA's LRO project scientist Richard Vondrak.
According to RTT News, if the results of the helium conclude that it is not from the lunar surface, the main source is likely from radioactive decay or from the spacecraft itself.