[meteorite-list] TLP article

From: Darren Garrison <cynapse_at_meteoritecentral.com>
Date: Sat, 04 Aug 2007 09:52:07 -0400
Message-ID: <8219b3dlq8h2rso23isc0o0n7324lhf4ns_at_4ax.com>

http://www.astronomyreport.com/Research/Astronomer_Offers_New_Theory_Into_400-year-old_Lunar_Mystery.asp

Astronomer Offers New Theory Into 400-year-old Lunar Mystery (8/2/2007)

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.
Received on Sat 04 Aug 2007 09:52:07 AM PDT