Step back from the crater to take in the diamond-shaped Aristarchus Plateau

wind ‘weathering’. The crater has well-defined ramparts rising 600m above the surrounding area, leading up to a sharp rim edge. Inside there are many terraces which lead down to a flat floor with a central mountain. The crater is 3.2km deep.

Stepping back from the crater itself allows you to take in the surroundings and the diamond-shaped region known as the Aristarchus Plateau. Aristarchus occupies the eastern corner of the diamond. The plateau has a brown hue compared to its surroundings and this is something which is interesting to bring out when imaging the Moon with a colour camera.

Southwest of Aristarchus by 65km (centre-tocentre) lies 35km Herodotus which, despite having a similar size to Aristrachus, couldn’t be more different in general appearance. Herodotus has a more typical lunar darkness to it. It is 1.3km deep and has a flat floor with only one 1.3km craterlet visible in typical amateur scopes. Herodotus’s rim is thin and worn, interrupted in the northwest by 4km Herodotus N. Herodotus is a much older feature than Aristarchus with an age somewhere between 3.2–3.8 billion years.

A number of smaller craters occupy the raised plateau such as 12km Raman to the west, 8km Väisälä to the east and 3km Freud which sits almost in the centre. A significant feature on the plateau is Vallis Schröteri. This is a fascinating valley which starts thin in the west, arches north getting thicker as it goes and then curves southeast to end just north of the mid-point between Herodotus and Aristarchus. The valley widens at its end-point in the east, into a feature informally called the Cobra Head, although it looks more like a python than a cobra. A rille passes down the centre of the head, which is a good test for a high-resolution imaging setup.

Visually, it’s probably easier to follow Vallis Schröteri from the 10km-wide Cobra Head. Heading north it immediately narrows to just 6km wide. About 30km north of the snake’s ‘nose’ the valley bends towards the northwest for a further 30km. At the end of this run, it then narrows to just 4km across. The valley then meanders for around 25km as it heads west before taking a sharp turn southwest. This is where things get tricky because over the course of its remaining 90km, it narrows to a width which will be too thin to follow with amateur equipment. As an exercise, try to see just how far you can follow it. Further cracks north of Aristarchus are known as Rimae Aristarchus.