Fig. 4
From: A new view on the solar wind interaction with the Moon
The back-scattered hydrogen ENA reflection ratio over the magnetic anomaly near 22° S and 240° E on the lunar farside observed from 200 km altitude on 17 June 2009. The maps show a unit-less reflection coefficient: neutral hydrogen number flux integrated over the specified energy range divided by total solar wind number flux integrated over energy and cosine of lunar latitude in the energy ranges a 150–600 eV. Black contours in the centre show the magnetic field magnitude at 30 km altitude obtained from Lunar Prospector data, with lines for 5, 15, and 25 nT. The dotted circle represents the region of magnetic anomaly and the dashed circle represents the region just surrounding the anomaly. b Context image taken from the Clementine grey scale albedo map where the regions M, E, and U indicate three sample regions inside the mini-magnetosphere, the enhanced flux region, and the undisturbed region, respectively [from Wieser et al. (2010)]