Hi Shaun,
The Moon WAS a very active place, but a very long time ago. A lot of the lunar geography can be readily assessed as very old or not by examining the surrounding geography.
Have a read through this post of a sketch I did of the crater Alphonsus. It details this very thing and how uncanny a time-line of lunar age & activity this area of the Moon is:
http://www.iceinspace.com.au/forum/s...&postcount=172
The Moon's "geology" & "geography" mirrors that of Earth's the main difference being there is no air or water to cause erosion.
There are also fault line escarpments (
The Straight Wall), shrinkage fractures (
Several concentric ones can be seen here), domes (volcanos that never erupted but swelled the surface up as the lava pushed from below), volcanos (see my post linked above).
Other tell-tale elements of 'young' geographic features are ray craters. Old, unflooded craters have had their rays obliterated by the ejecta from subsequent impacts covering over the older rays. Younger impacts have their rays largely intact (
Copernicus crater).
Landslides are also observable on the inside and outside of craters. These can also be easily seen in Copernicus. These landslides appear as concentric terraces. These landslides are evidence of a very dry and sandy lunar soil - the initial impact forms the crater, but as the soil is fine textured too, gravity eventually pulls down the steep walls outside and in of the crater, resulting in their concentric appearance -
the very same reason for which it is very, very dangerous for kids (and adults) to dig holes that are very deep at the beach and other sandy areas as these can and do tragically collapse.
One quirky feature of the Moon is purely a trick of our imagination. Our eyes are hard-wired to look for patterns and familiar shapes. This can result in our eyes 'seeing' alphanumeric characters along the terminator as shadows creep along. Probably the most famous of these is
The Lunar "X". I've also seen
an Owl and a curious collection of
Christmas Tree, butterfly and an olde cross. The most fantastic pattern I've seen though is
a shadow with an uncanny resemblance to the outline of Australia!.
There is one fantastic website that will help you identify many, many other geologic and geographic features on the Moon.
Observing the Moon along the Terminator is a fantastic source of information that I regularly go over to help me define what it is that I've been seeing.
Mental.
