Astronomer Offers New Theory Into 400-year-old Lunar Mystery

Columbia astronomy professor Arlin Crotts thinks he has solved a 400-year-old mystery: the origin of strange optical flashes often reported as appearing on the moon’s surface.

Transient Lunar Phenomena (TLPs), in which the lunar surface reportedly changes in brightness, blurriness or color, 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 hotly debated. The TLPs typically cover a space of a few kilometers and last for several minutes.

Crotts 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” says Crotts, “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 was a remarkable similarity in the pattern of outgassing event locations recorded by spacecraft across the face of the moon and reported TLP sites.

The pattern was further strengthened after Crotts performed a statistical test to rid the sample list of false reports and one time events that might not represent true outgassing sources. “The result,” says Crotts “shows that some lunar event sites that were the focus of great observer excitement over recent decades disappeared from the more highly refined list of TLP sites.” Crotts used two catalogs of such sightings amassed and edited three decades ago by now retired astronomers Barbara Middlehurst and Winifred Cameron.

Crotts says this research might lead to optical imaging of the lunar surface that could monitor how, when and where gas escapes from the moon. While the exact composition of this gas is largely unknown, he explains, hints from previous measurements indicate that it might contain substances beneficial for future moon explorations, especially water.

Until now, Crotts says two factors have worked against researchers solving the mystery of TLPs. Historically, outgassing has often been discussed by scientists, but many have considered the moon volcanically dead despite moonquakes and episodes of gas, such as argon, observed coming from the lunar surface. Another deterrent to researchers is the daunting volume of visual data associated with TLPs – a fact that plays to Crotts’ particular research interest and skills.

Along with collaborators Professors Paul Hickson from the University of British Columbia, and Thomas Pfrommer and Cameron Hummels of Columbia, Crotts recently built the robotic camera at Cerro Tololo Inter-American Observatory in northern Chile. It will automatically scan the moon for TLPs every few seconds and produce an unbiased map of the distribution, free of potentially flawed sightings due to human error, poor equipment, or improperly recorded observations that have dominated TLP studies until now. The scientists are planning even more monitors and hope they will establish with much greater accuracy the exact locations of gas leaks on the moon.

Crotts says improved TLP maps are already pointing to intriguing features on the lunar surface, and he is currently preparing a separate article on that subject.

Source: by David Poratta, Columbia University

Related stories:

NASA Engineers Complete Engine Test Series For Ares I Rocket
(PhysOrg.com) -- Engineers at NASA's Marshall Space Flight Center in Huntsville, Ala., have completed a series of tests on a key component of the J-2X engine. The J-2X powers the upper stage of the Ares I rocket, which will launch human explorers to the International Space Station and to the moon.
Phoenix Camera Sees Morning Frost at the Landing Site
(PhysOrg.com) -- The Surface Stereo Imager, or SSI, on NASA's Phoenix Mars Lander has seen water frost on the ground around the spacecraft's landing site.
China's lunar satellite survives eclipse: state media
China's first lunar satellite, which has been orbiting around the moon for nearly nine months, has withstood the test of a solar eclipse that cut its solar energy supply, state media reported Monday.
China's lunar satellite faces eclipse challenge
China's first lunar satellite, which has been turning around the moon for nearly nine months, will be stripped of its solar energy supply Sunday when the earth eclipses the sun, state media said Friday.
NASA delays robotic moon mission until 2009
(AP) -- NASA has delayed the launch of an unmanned spacecraft to the moon to scout for potential landing sites for astronauts.
Ready the telescopes: partial lunar eclipse on Saturday
People across the world will have the chance to see a partial eclipse of the Moon on Saturday.
Space Shuttle successor will not fly before 2014: NASA
NASA announced it has pushed back the launch of the Orion, the spacecraft designed to replace the agency's aging space shuttle fleet, by one year to 2014.
A Flash of Insight: LCROSS Mission Update
There are places on the Moon where the sun hasn't shined for millions of years. Dark polar craters too deep for sunlight to penetrate are luna incognita, the realm of the unknown, and in their inky depths, researchers believe, may lie a treasure of great value. NASA is about to light one up.

News discussion:

TLP"s are not a mystery to Plasma Cosmology in Space & Earth science news