Flamsteed P is a crater rim in the Southern Oceanus Procellarum. It is what remains visible of one of numerous former craters that were flooded in the last of the great Mare extrusions about 2 billion years ago.
The reason why the southern part of Oceanus Procellarum is busy with such crater rims is probably because the lava was shallower here than elsewhere, and that may be because the region lies on the edge of a putative giant impact basin known as Gargantuan: elsewhere the surface was lower and lavas deeper.
On the 5th January when I observed Flamsteed P for the first time, seeing was pretty terrible, despite good transparency. I did however pick up most of the larger rim segments and many of the smaller craterlets surrounding it. Some low hills poking about the mare lavas just appeared as white spots. The central peaks of Flamsteed were not visible: possibly they were in shadow.
America’s first soft lander spacecraft, Surveyor 1, landed within Flamsteed P, at the spot marked by the X. It was important in demonstrating that the lunar regolith was stable and thick enough to support a spacecraft, as renowned lunar scientist Tommy Gold had predicted that the dust layer would be so thick that any spacecraft would sink without trace. He was wrong, and the rest is history.
January 7, 2012
peterjmayhew
