Diana Larking of Gore asks :-

For several months the new moon has been accompanied by an out of focus image, lying adjacent. One new moon I saw had an additional red crescent wedged in between. Is this related to the recent unpredictable weather patterns?

Alan Gilmore, an astronomer at the University of Canterbury's Mt John Observatory, responded.

Firstly there is no connection between the moon's appearance and the weather. Sometimes clouds will add haloes around the moon, but that is all. I know that Mr Ken Ring is getting a lot of publicity, and selling an expensive book, by purporting to predict weather by the moon. None of his theories have any basis in reality.

If you are seeing the 'out of focus' moon with the naked eye then I suspect that you are seeing the phenomenon of 'the old moon in the new moon's arms'. You can see the 'dark' part of the moon glowing faintly beside the bright crescent. The scientific name for this is earthshine. Seen from the moon, the earth appears like a full moon but much bigger and brighter. The light from the 'full earth', reflecting off the moon, that makes the dark part of the moon visible.

Alternatively, if you are viewing the moon through binoculars or a telescope then it is possible that you are seeing a 'ghost' image. These are caused by reflections between the lenses. The reflections ('ghosts') are particularly noticeable with objects like the moon because of the dark background.

A telescopic or binocular view is the only explanation I can think of for the red crescent. It would be caused by chromatic aberration: the colours not being exactly focused together. This is a common failing of many telescopes and binoculars. Again it is more obvious with the dark background. If chromatic aberration is the cause then I would expect you to see a blue-violet crescent on the other side of the white crescent.