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Transient Lunar Phenomena |
Transient Lunar Phenomena (or TLP) is the term given to temporary short term occurrences that are sometimes observed on the Moon. They may take the form of glowing patches, mists, spots, flashes, etc.
TLPs have been observed for as long as telescopes have been pointed at the Moon. Because of their elusive occurrences, professional astronomers have been loath to accept them as much more than optical illusions or outright fabrications. However a number of prominent astronomers have observed TLPs including William Herschel, E.E. Barnard and Patrick Moore.
TLPs challenge the traditionally held view that the Moon is a dead world. The proofs for their existence have only really come about in the last 100 or so years, because of technological improvements to observations. The Russian astronomer Nikolai Kozyrev obtained a spectrogram of one in 1958, showing the emission spectrum of carbon vapour. Apollo 11 astronauts were able to confirm a TLP event happening on the Moon from orbit.
The main theories as to the cause of TLPs include:
Some kind of lunar out-gassing, either caused by geological activity, or...
...tidal stress induced by the Earth on the Moon. By some mechanism the gas fluoresces or it carries lunar dust up where it catches the sunlight.
Some TLPs seem to occur only when there is large amount of solar activity present. Some astronomers theorise that high-energy particles from the Sun are causing lunar rocks to fluoresce.
Some regions seem prone to TLP, for example the craters Aristarchus, Herodotus and Schroters Valley. TLP also seem to occur at the edges of the lunar mare. Again this seems to hint at a geological cause.
Some TLP effects may be the result of meteor impacts on the Moon. Some observers have tested this theory by examining the dark portion of the moon at times when meteor showers are occurring, and it has been shown that groups of observers are able to confirm the same impact on the moon.
CMOS and CCD cameras have made astro-imaging affordable for many people. Some amateur astronomers and astronomical groups (professional and amateur) have created automated telescopes that record the Moon. Anomalous frames are detected by computer. Meteor strikes and asteroid/debris bodies have been seen passing in front of the moon this way.
Whilst the cause of TLPs has not been pinpointed, it would seem that astronomers can no longer doubt that that the Moon is not as dead as traditionally thought.
