Hercules G stood out in very sharp relief near the middle of Hercules,
and some of the central mountains of Atlas were prominent. At the
time I was looking at them, I suspected they were some craters I had
seen before, but I wasn't sure. I showed them to Halina, and she
gasped, "Wow! It looks like a painting! I didn't realize it would
look like this! This is cool!"
Lacus Mortis (JRF <freeman _at_ netcom.com>)
The western side of the Lake of Death contains a couple of fine
rilles -- the Rimae Burg -- associated with crater Burg.
Lacus Mortis (David North <d _at_ timocharis.com>)
It's fun to bounce around the rill structures in the area of Lacus Mortis.
Inside Lacus Mortis, Rima Burg is an unusually wide rille which looks
more like a canyon or valley.
(Hmm, I notice that contrasts with Jay's comment, above, that Rimae Burg
are fine. Perhaps this rille system is more than usually variable according
to light conditions ...)
Lacus Somniorum (JRF <freeman _at_ netcom.com>)
A rille system -- Rimae Daniell -- associated with crater Daniell
begins about half way between Posidonius and Burg, and extends west
northwest, increasing in complexity with distance.
Using the 13" f/5.6 stopped down to 10" aperture at 120X and 180X,
the crater Posidonius was right on the terminator and showed a lot of detail.
There is a small crater near the center of the much larger one,
this little crater is Posidonius A and it is offset within the main
crater to the south. Then to the north and west of Pos. A is a
circlet of four little peaks on the floor of the main crater.
The eastern rim is in bright sunlight and there is some terracing
of the crater walls. The western rim casts a shadow across the
floor of the crater and it shows a very saw-toothed shape.
There are several rilles within Posidonius, some appear to radiate
out from the center. All in all, lots of fun detail to be seen.
Posidonius (JRF <freeman _at_ netcom.com>)
Walled plain Posidonius is noted for a floor that is notably lighter
in intensity than the surrounding Mare, through much of the lunation.
Posidonius is a "landmark" feature, easily recognized and useful for
orientation. Posidonius and its southeast adjoining neighbor,
Chacornac, are crossed by a prominent rille system.
Posidonius is criss-crossed by rilles, and there are also rilles
arcing just inside the crater walls; but there's also a mountain range
inside the east wall which can be confused with a rille in some lights.
Morio Higashida has a terrific high-res
image of Posidonius showing the detail inside.
Thierry Legault's
CCD image of Posidonus at the edge of Mare Serenitatis.
Posidonius (David North <d _at_ timocharis.com>)
Even in unfavorable illumination, the t-structured rilles in Posiedonius
were still above the verge, this side of the pale.
Thierry Legault's
CCD image of Posidonus at the edge of Mare Serenitatis.