Okay... I had an idea for my "Shades of Gray" story, that I thought would be cool, and also amusing, but I'd like to know if it's scientifically possible, before I go ahead and use it.
In the story, a human asks one of the Grays if their world (Orvan) has a moon. The Gray responds, by saying "Sometimes", to a puzzled human.
My thought was this...
That since the Gray's homeworld is in the Zeta Reticuli system, which is a binary, and orbits the second star, that perhaps orbiting the FIRST star, is a small planetoid, maybe like Phobos or Charon, that has such an elliptical orbit, that once every one hundred thousand years or so, that small planetoid gets close enough to Orvan, to be temporarily captured by its gravity, and orbits it as a moon, until the next interval, when Orvan's gravity again flings it back into its old orbit, around the FIRST star.
I was wondering if this concept is at all doable?
What is interesting is what you describe is somewhat similar to the concept of 'Planet X' (aka Nibiru) in UFO mythology (something you already seem familiar with based on your Zeta references). Basically the premise is that a large object has an elliptical orbit with our own sun (much like many comets like Haley's do) and this object comes around every 11,000 years and which due to a close pass to earth makes a mess of things. The poles shift, massive earthquakes and meteorological phenomena result. The present state of human civilization and technological advancement collapses (like Mu and Atlantis). An interesting book on the subject that I just happen to be reading at the moment is called 'Worlds in Collision'
by Immanuel Velikovsky. He makes the case for sudden earth changes using a plethora of examples. Such as the ice sheets from the last ice age not lining up with our present poles (they seemed to skip Siberia and were present in Africa). Mammoths frozen to death with food in their mouths. Numerous native and religious references to the sun stopping and even rising in the wrong direction. The great flood from the bible matching other floods from other cultures. Pole shift evidence from the mid-Atlantic ridge. Tibetan references to the Himalayas being underwater and much more... Incidentally we are about due for another pole shift (aka Armageddon) which if the Mayan calendars are correct should happen around 2012 and send human civilization back into another stone age. Lot's of story ideas available from the planet X mythology...