Favorite LPODs of the Year - Lake of Death
Explanation:
Do you consider Lacus Mortis - The Lake of Death - a crater? Because of the mare-like term "lacus" some observers just
see it as a patch of mare material linking Mare Frigoris and Lacus Somniorum. But if you linger, taking your eyes off the
challenging rilles and superposed crater Burg, you will easily notice low walls that enclose nearly the entire lake. I
say "walls" rather than "rim" for the latter term implies a rampart that projects above the surrounding environs, and
these don't. Lacus Mortis is a depression lower than most of its surroundings, especially the rubbly plateau to the west.
Notice the faint diagonal lineations in the rubbly material? They are probably flow marks in this jumble of ejecta from
the Imbrium basin. Notice also that the walls of Lacus Mortis do not define a circle or an ellipse - they have distinct
straight edges. These linear wall segments are part of the lunar grid system, marked also by the polygonal sides of
Ptolemaeus, the Straight Wall, the Alpine Valley and other straight features. Some
of these linear features are related to basins, but others could have formed by tidal stressing early in lunar history
when the Moon was much closer to Earth.
—
Chuck Wood
Technical Details:
Imaged 18 July 2003 in Hong Kong with a 212 mm Newtonian Cassegrain and a 2x Barlow and Phillips Toucam Pro webcam. 212 frames were stacked and the seeing was good (8/10) and transparency fair (5/20).
Related Links:
KC Pau on Observingthesky.org
Lunar Orbiter image
