June 17, 2004

Marsh of Epidemics

Image Credit: Giorgio Mengoli

Marsh of Epidemics Some lunar backwaters are pretty interesting. Palus Epidemiarum is a marshy region squeezed behind both Mare Humorum and Mare Nubium. To be lava covered it must have been a depression, but there is no convincing evidence for a large crater or basin. To the west of this diseased area is a similar poorly defined mare area that the IAU gave the inappropriate name of Lake of Excellence. Perhaps both of these odd named low zones are depressions beyond the rim of Humorum - like the Frigoris, Aestuum and Vaporum lowlands that encircle Imbium. In fact, these marshy areas are inside the indistinct outer basin ring of Humorum. Epidemiarum contains a dense network on intersecting linear rilles that are difficult to see with small telescopes. They are not obviously related to Humorum or any other structural feature, but appear like cracks on the crust of baked bread - perhaps western Epidemiarum is a broad uplifted area. This image contains two concentric craters - Hesiodus A near Pitatus and Marth. Each of the outer craters appear to be normal impact craters, but their inner rings could be volcanic. Finally - do you notice the two domes? One is just west of Kies and the other is on the floor of Capuanus. Technical Details: Takahashi cassegrain Mewlon 210 - 8" F/11.5 - 2415mm and HX516 ccd color 5300K Related Links: Lunar Orbiter IV View Giorgio's High Resolution Imaging Yesterday's LPOD: A Classic Returns! Tomorrow's LPOD: Frigid Buddies: Aristoteles and Eudoxus