Origin of pit chains in the floor of lunar Copernican craters

Abstract

There are small pit chains in the floor of lunar Copernican craters. They are usually so small in scale that there are few lunar spacecrafts to detect their detailed morphology. Combining camera data from Lunar Orbiter, Lunar Reconnaissance Orbiter (LRO), Kaguya and Chang’e-1 missions, 5 representative large Copernican craters on various terrains of the lunar surface are chosen to study the origin of the pit chains in the crater floor. The morphology and distribution characteristic of the pit chains are referred by the high resolution images in this research. It is suggested that it is the magma activities from the subsurface magma layer combining with the existence of fractures and faults under the crater floor that leaded the formation of the pit chains. The model is further verified and discussed using the regolith thickness data in the crater floor. Our model suggests that the pit chains are still developing in the floor of the Copernican craters and the Moon may not be totally cold. Finally, the model limitation and potential future work are discussed based on available data.