After a fantastic Sunday, the skies remained clear with a 4 day moon shining brightly as the sky began turning from blue into black. The libration really brought the north eastern corner into view, an area that I have yet to truly explore.

I was struck by how much Mare Humboldtianum was visible. This infrequently seen structure was crying out for a capture. I made a composite of 2 frames stretching from friends Atlas & Hercules, Endymion to Mare Humboldt. It is interesting to note the relative structures of each crater.

Endymion Humboldt 20160313 brighter


  • Hercules                               flat, domed floor
  • Atlas                                      fractured with several rilles and faults
  • Endymion                            flat, dark lava flooded floor
  • Mare Humboldt                  lava filled impact basin with prominent escarpment

Note also the mountain silhouetted against the skyline – you wouldn’t want to be in a low lunar orbit around there!

Further south is Mare Marginis, another infrequently seen region. I have had this on my wish list for a while as the northern corner of Mare Marginis is covered with unusual dusting of bright, magnetic material known as the Mare Marginis Swirls. Apparently, no one knows what these bright deposits are! Who says the moon is boring!  Note the image is rotated.

Mare Marginis 20160311 copy

Further to the south is the ruined crater Jansen. With this low sun angle, Jansen appears as if it is filled with rubble! Prominent to the south is the arcing Rima Jansen, a fault in the crater surface. It clearly stops at the crater walls of Fabricus and Jansen itself.

Jansen 20160313 copy