Eratosthenes

My next stop along the half-moon terminator was Eratosthenes. Named after the father of geography, inventor of the system of latitude and longitude, and all round Greek genius, Eratosthenes is located on the south edge of Mare Imbrium at the western end of the Montes Appenninus. It's a relatively deep crater that catches the eye due to it's prominent location and proximity to the crater Copernicus.

Similarly to my observations of Plato described in my previous post, I was dodging light cloud for much of the session. Here's the best shot:


Eratosthenes is the crater towards the bottom-left. The depth of the crater and terraced inner rim are clearly seen. There are also multiple central peaks visible and little evidence of lava flooding which suggests the crater may be younger than flooded craters such as Plato. In fact Eratosthenes is believed to be around 3.2 billion years old and its formation marks the start of the Eratosthenian Period which is partly characterised by reduced volcanic activity.

Looking closely at the bottom-left quarter of the picture it is possible to see the ejecta from the neighbouring crater Copernicus, which show up as lines of lighter coloured material. The three craters at the top of the picture, moving left to right, are Timocharis, Archimedes and Autolycus.