It’s a mystery that has vexed astronomers for possibly 1500 years—odd, optical flashes that occasionally appear on the surface of the moon. The flashes were dubbed transient lunar phenomena, or TLPs. The lunar surface seems to change in brightness, blurriness or color. TLPs can last for a few minutes and cover a few kilometers.
Now an astronomer at Columbia University thinks he knows what’s causing the strange optical effects. Other researchers have conjectured that the release of gas from under the surface might be involved. And Columbia’s Arlin Cotts has uncovered a strong statistical relationship between outgassing events that were documented by spacecraft and recorded accounts of TLPs. The 1971 Apollo 15 flight and the 1998 Lunar Prospector robotic mission provided key data.
The research could lead to a more comprehensive understanding of how, when and where gas escapes from the moon’s interior. If it includes water vapor, the gas could be useful to capture. On the other hand, it looks like the gas might also contain significant amounts of radon. So any moon bases could have the same problem many homeowners do on earth—radon in the basement.