Vol 47, No 4, April 2010 - BAA Lunar Section

Manilius and nearby dome-like elevations
Phil Morgan reports: ‘I made a sketch of what appeared to be a very large and rough dome just northeast of
the crater Manilius on the evening of 2010 February 20 (above, right). Just like the previous observation I
was limited to only about 20 minutes of clear sky, so again a rather rushed effort to get things down before
lights out. I have to say that I have no certain information that this is indeed a large dome. All I can say is that
it looked like one at this colongitude, and just like Rumker it had a rough and lumpy summit area. It could be
just the denuded remains of a once grand mountain mass. I’ve tried to find some images at a similar colongitude,
but with only limited success. All that I found was the rather low-res image on page 92 of the Atlas of
the Lunar Terminator taken Col. 351°. If you should know of anything else or have any information I would
be pleased to see it.’
On checking the SPA/BAA Lunar Section database there were two other observations of Manilius, one by
Massimo Chiarini (2000 February 12) and the other by Grahame Wheatley (2001 October 23). Massimo’s
observation shows just the crater at a different illumination to Phil’s, but in one of those remarkable coincidences
we’re sometimes treated to, Grahame’s observation (featured above, left) depicts almost precisely the
same area as Phil’s, and it is made under nearly the same illumination conditions (a slightly lower Sun in
Grahame’s). As might be expected of two such skilled observers, they show a very good degree of congruence;
the dome-like elevation mentioned by Phil is also shown in Grahame’s observation. I tend towards the
idea that the features represent pre-mare flooding heights that were covered with lava.
Join us at our Yahoo! Group — topographic studies
If you’d like to see more of the BAA Lunar Section’s observations, along with some of those mentioned
in this LSC, you’re most welcome to join our Yahoo! Group at:
http://uk.groups.yahoo.com/group/baalunarsection-topography/
It’s easy to join – simply follow the on-screen instructions and I will sign you in as quickly as possible.
Peter Grego
BAA Lunar Section Circular Vol. 47 No. 4 April 2010 7