Last year the Stonehenge Hidden Landscape Project was surveying at Durrington Walls henge and they thought the Geophys had turned up a circle of buried stones. The circle was much larger than Stonehenge itself and appeared to fit into the giant proportions of the bank and ditch system at Durrington Walls. It was just a matter of time before archaeologists got out their spades and investigated what their radar images had shown up. It seems there are no buried stones. All they found are holes in the chalk archaeology that once held wooden posts (but were filled in with lumps of chalk and chalk debris, presumably what had been dug out in the first place). See http://phys.org/print390638952.html … and we learn the researchers are now speculating the circle was never finished and was abandoned. The same story pops up on most media outlets and will be a feature of the archaeological press in later months (when mor information is gleaned). Speculation at the moment is that the Beaker Folk turned up with a different religion and supplanted the previous belief system (whatever that might have been) hence the abandonment in the middle of construction. Little is known about the Beaker Folk but there is evidence they were at Stonehenge. However, the idea of an ancient religion is probably the wrong end of the stick and it is likely that whatever object in the sky was the focus of attention, changes in the orbit may have led to a re-evaluation of the energy expended on the new circle. Stonehenge itself was revamped on several occasions so something was happening to make them switch plans. The theory that a comet was in the process of breaking up at this time has been suggested by astronomers but has not percolated down to archaeologists – as yet. Moe Mandelkehr in his '2300BC Event' assumed a large meteor storm was in play – yet a comet breaking apart, into two or three pieces, may be all that is required to explain the change of plan. The other possibility is that a comet broke apart into a lot of pieces and subsequently became invisible, or mostly invisible (flaring up now and again) as that appears to be the situation in the second millennium BC. We don't have descriptions of comets looming large but a focus on pieces of former comets (such as the Greek Heruclidae, or pieces of Herakles).