L57: Reiner Gamma

Reiner Gamma is a bright swirl on the western borders of Oceanus Procellarum, and close to crater Reiner. The feature is not elevated above the mare, but is due to a different hue of the soil. The lunar swirls are associated with strong magnetic anomalies that are believed to keep the solar wind from darkening the mare material. Observed during high sun the feature was quite distinct. The ‘tail’ could be traced to its full extension. Consulting maps and images the ridge indicated in the sketch seems to be a misrepresented part of the swirl.

Reiner gamma
Sketch made 10 July 2014 using a SkyWatcher 10″ and a TeleVue Nagler zoom 3-6 mm. North is down.