Expert: Steven LJ Russo - 9/25/2006

Question
Dear Mr Russo,

A couple of weeks ago I was observing the Moon from my
windown in London, England when it was more than half full and
there was little in the way of cloud cover to obscure my view.

Strangely enough (and you may wonder what I was smoking at
the time!) but  I noticed that each time I looked, expecting to see
it had moved along it's usual track across the sky', it (instead)
appeared to be completely stationary and didn't actually 'go
anywhere' for more than 30 minutes!

Frustratingly, the clouds closed-in and my viewing time was over
but I can't even begin to understand what I had witnessed. Was I
dreaming or is there a point in the lunar calendar when the
moon 'stands still' somehow?  

I have tried to look it up on the web but I still can't find anything
that I can understand as being the event I saw recently.

Many thanks for your time.

Answer
Lesley:

I am not sure what you may have witnessed, but the Moon cannot stand still, or appear to stand still.

The Moon moves around the Earth, and of course the Earth rotates on its axis.  That combined, would make the moon move 15 degrees per day in the sky.

So the ONLY way that the moon would not move, is if it DID stop, AND the Earth also stopped rotating.  Neither of those things would ever happen, well maybe 5 billion years from now when the Sun dies...

So you may have just seen some illusion of some kind.

Steve