Transient lunar phenomenon
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This map, based on a survey of 300 TLPs by Barbara Middlehurst and Patrick Moore, shows the approximate distribution of observed events. Red-hued events are in red; the remainder are yellow. |
A
transient lunar phenomenon (TLP) is a sometimes inexplicable change of color or shape seen on the surface of the
moon. Some may be caused by gas escaping from underground cavities after
moonquakes. A number of these gaseous events have displayed a distinctive reddish hue, while others have appeared as white clouds or an indistinct haze. The majority appear to be associated with clefted crater floors, the edges of
lunar mares, or in locations linked by geologists with volcanic activity.
In
1866, the experienced lifelong lunar observer and mapmaker
Johann Friedrich Julius Schmidt made the claim that
Linné crater had changed its appearance, from a normal, relatively deep crater to a mere white patch. A controversy arose and the claim remains unproven. No further changes have been observed in the crater; if true this would not be a transient change but a permanent one.
On
November 2 1958, the Russian astronomer
Nikolai A. Kozyrev observed an apparent outgassing of vapor near the central peak of
Alphonsus crater. He took
spectrograms that appeared to show the presence of carbon vapor.
Audouin Dollfus of the
Observatoire de Paris observed a series of glows on the floor of
Langrenus crater using the one-meter telescope on
December 30,
1992. These glows changed form with time, and Professor Dollfus expressed the belief that this was likely a gaseous emission. The cracked floor of the crater may have been the source of the gas.
On
April 23 1999, amateur observers reported another TLP event in the vicinity of the "Cobra Head", the name for the bulbous start of the
Vallis Schröteri adjacent to the
Aristarchus crater. The
Clementine spacecraft took before and after pictures of this region, and definite color changes were observed.
Other near-side
craters where TLP have been reported are
Grimaldi,
Hercules,
Plato,
Theaetetus and
Thales.
*
The Kozyrev Observations of Alphonsus, PASP 71 (1959) 46*
Patrick Moore,
On the Moon, Cassel & Co.,
2001, ISBN 0304354694.
*
Chronological Catalog of Reported Lunar Events, July 1968 — NASA report on TLP sightings from 1540 to 1968
*
"Light Side of the Moon" — An article from the
Fortean Times for December 1997 by the astronomer Peter Grego
*
Lunar Transient Phenomenon Research Program by David O. Darling.
*
Transient Lunar Phenomena (and other weirdness) — Essay on TLP followed by links.
*
New Research into Mysterious Moon Storms — new investigation of an old Apollo experiment might provide explanation to some TLPs.
