US professor unravels mystery of outgassing events on lunar surface

New York, June. 27 (PTI): A Columbia University professor of astronomy has claimed to solve a 400-year-old mystery about the origin of strange optical flashes often reported appearing on the moon's surface.

Transient Lunar Phenomena (TLPs), in which the lunar surface changes in brightness, blurriness or colour, have been photographed and observed by thousands of astronomers over the centuries. Yet explanations of why they occur and even their reality as true lunar phenomena have been largely debated. The TLPs typically cover a space of a few kilometers and last for several minutes.

Prof Arlin Crotts said he has uncovered a strong statistical relationship between TLPs and so-called outgassing events on the lunar surface. Outgassing occurs when gases trapped beneath a moon or planet are released and, if only briefly, become part of the object's atmosphere. A key component of this gas is radon.

"People over the years have attributed TLPs to all sorts of effects: turbulence in Earth's atmosphere, visual physiological effects, atmospheric smearing of light like a prism, and even psychological effects like hysteria or planted suggestion," Crotts said. "But TLPs correlate strongly with radon gas leaking from the moon. No earth-bound effect can fake that."

To arrive at his theory, Crotts correlated TLPs with known gas outbursts from the lunar surface as seen by several spacecraft, particularly NASA's Apollo 15 mission in 1971 and the robotic Lunar Prospector in 1998. What he discovered, Crotts said, was a remarkable similarity in the pattern of outgassing event locations recorded by spacecraft across the face of the moon and reported TLP sites.