NASA finally answers lingering lunar question

The big experiments in space might seem like they're happening on Mars or even further afield, but NASA's latest discovery proves there's plenty to learn closer to home. Thanks to the Lunar Atmosphere and Dust Environment Explorer (LADEE) spacecraft, we now know that the atmosphere of our own moon contains neon, something suspected all the way back in the days of the Apollo missions, but until now unconfirmed.

"We were very pleased to not only finally confirm its presence," Mehdi Benna of the Goddard Space Flight Center, and lead author of a paper describing results from the LADEE experiments, said, "but to show that it is relatively abundant."

The paper, detailing some of the findings from the Neutral Mass Spectrometer carried on the LADEE craft, was published in late May, in Geophysical Research Letters.

Abundance, though, is a relative thing. While a glowing moon might be cool, sadly the atmosphere is nowhere near dense enough to do so.

That doesn't mean there's not enough going on there to intrigue scientists, however. Researchers have long pondered on the exact origins of the various gases – predominantly helium, argon, and neon – that make up the moon's exosphere, most but not all of which comes from solar winds.

In fact, the team discovered that lunar rocks are also responsible, and that the proportions of the gases fluctuate over the course of a day.

"Their relative abundance is dependent on the time of day on the moon," NASA says, "argon peaks at sunrise, with neon at 4 a.m. and helium at 1 a.m."

Some argon, for instance, comes from the decay of radioactive potassium, while as much as a fifth of the helium there is believed to be the product of radioactive thorium and uranium.