NASA’s Lunar Atmosphere and Dust Environment Explorer – known as LADEE – found neon in the lunar atmosphere during its 2014 mission, data released shows.
“The presence of neon in the exosphere of the moon has been a subject of speculation since the Apollo missions, but no credible detections were made,” said Mehdi Benna of NASA’s Goddard Space Flight Center in Greenbelt, Maryland and the University of Maryland, Baltimore County.
“We were very pleased to not only finally confirm its presence, but to show that it is relatively abundant.”
The neon is very sparse, however, as the moon’s atmosphere is extremely tenuous – about 100 trillion times less dense than Earth’s atmosphere at sea level.
NASA explains:
“Most of the moon’s exosphere comes from the solar wind, a thin stream of electrically conducting gas blown from the surface of the sun into space at around a million miles per hour. Most of the solar wind is hydrogen and helium, but it contains many other elements in small amounts, including neon. All these elements impact the moon, but only helium, neon, and argon are volatile enough to be returned back to space. The rest of the elements will stick indefinitely to the moon’s surface.”
LADEE has confirms that the moon’s exosphere is made up of mostly helium, argon, and neon, with their relative abundance varying according to the time of day on the moon.
LADEE was launched in September 2013 and entered its science orbit around the moon’s equator in November that year. In March 2014, NASA extended its mission operations following a highly successful 100-day primary science phase. The spacecraft lacked fuel to maintain a long-term lunar orbit and crashed into the surface on 17 April, 2014.