Lights glow on Moon
Light site: The mighty crater Langrenus, 136 km across
New evidence shows that the Moon is not a totally dead world as was thought by many astronomers. It does still occasionally stir with activity.
Even though they have been reported from time to time for hundreds of years claims of changes on the lunar surface have always been controversial. Many scientists have dismissed the occasional reported sightings of glows and mists hanging over certain lunar features.
Now a French astronomer has obtained some of the most definite proof yet that occasionally something does disturb the lunar surface.
It was seen in 1992 by veteran lunar observer Audouin Dollfus of the Observatoire de Paris using the one metre (39 inch) Meudon reflecting telescope. He has only just finished analysing the results, and has submitted them for publication.
On 30 December, he noticed a series of glows on the floor of the large crater Langrenus. They were definitely not there the day before. Professor Dollfus observed them for several days before they faded.
Each time he returned to the telescope he noticed that the shape of the glows had changed.
He believes that the glows are due to escaping gas that lifts dust above the lunar surface into sunlight.
Some lunar observers have expressed surprise that such a mist should have been seen above Langrenus which was not regarded as a prime candidate for lunar changes.
Professor Dolfuss points out that Langrenus, when observed in detail, has an extensive series of fractures on its crater floor and the gas could be escaping from these.
So-called "Transient Lunar Phenonemon" (TLP) have been reported from time to time but definite evidence has been lacking.
Man on the Moon
In 1994, the Clementine lunar orbiting satellite observed the crater Aristarchus before and after a TLP was seen from the Earth. Clementine spectral data suggested that parts of the crater had changed colour slightly.