Erosional Features Analysis Erosional Features Download gif download gif Was water the mechanism that caused the sinious rills seen on the visible face of the moon. Lava sculpting has been the traditional answer, and it has some merit. In a vacuum there is very little heat loss.
Molten rock tends to stay molten much longer than it does here on earth.
Its natural tendency is to flow down slope and seek the lowest point to puddle. Maria are extreme examples of this puddling mechanism. But the available lava phase of the moon's history came and went, by about 2.6 billion years ago. And sometimes there is no puddle. Also, some of the erosional features on the moon are younger than the last available lava supply.