Forefront the Manilius crater that is located on the
northeast edge of the Vaporum Sea with diameter of 39 km,
shooted by Achille Giordano of the GLR group.
Immediately to South of the crater a elusive crack is
visible, similar to a diagonal line first observed by Pau
(from the observer who his name is K.C. Pau a member of GLR
GROUP).
For reference on this formation and to a dome near Manilius
see to the description in
Selenology Today n°3, in the
article of Lena, Wöhler, Pau and Bregante.
Probably this elusive crack, damaged, not visible in the
images of the Lunar Orbiter but identifiable in the images
of the probe Clementine, is a graben formed from the stress
originated from a pressurized dike that it has not caught
up the surface but is gone up, through fractures of the
crust, to low deep; a mechanism suggested from Petrycki ed Wilson (1999) for rima Sirsalis and rima Parry V.
To the West of Manilius is observable the presence of a
series of domes, some already seen and presented in our map LAC 59 . The description of this rima and of these domes will come reported in an article in the next number of
Selenology Today (# 9). With a telescope of only 125 millimeter, Achille has shoot the formation of the caldera INA (see the green arrow), that it appears as a small
sinking to the north-west of Manilius (see the description of INA in Nuovo Orione november 2007, pagg. 34-38 , I Vulcani della Luna di Lena e Bregante GLR GROUP). ![](http://digilander.libero.it/gibbidomine/lacus.jpg)
Ina looks like a depression, sure a spectacular formation,
from the diameter of approximately 3 kilometers and a depth
of 30 meters and has been considered, still from the
analyses executed on the photos of the Apollo missions, a
caldera. Good shoot Achille!! The good optical quality,
associated to good seeing conditions and a favourable
condition of lighting has allowed you to catch eluding
details. Ina is localized to the coordinates of 18.7° N
and 5.3° E, and represents a reason of deepening for the
amateur astronomers that want to participate to a wider plan
of studies, beyond to verify the limits of resolution of the
own telescopes.
INA is a difficult detail, like shown (L99) by Wood, and today the shots have been obtained with great telescopes, like in the case of Higgins. Also Paolo Lazzarotti, with its
Gladio, has resumed INA and domes, under moderate solar light. Which further fine details we will be able to emerge from his telescope under a good seeing and one good
solar oblique light ? Which results will turn out with the use of narrow band filters, already used by R. Evans of the GLR, on so little extended formations, as just INA, obviously by
using telescopes of great diameter? And still: INA is localized on a low plateau or is part of a dome ?