Thursday, February 10, 2011
Mons or 'Dome' Maraldi?
Maraldi, with a widest diameter of 35km is an interesting feature visible after 5.6 days of lunation. It is an eroded circular formation with few high and damaged walls. Its floor is dark and filled with lava.
Particulary interesting through my telescope is Mons Maraldi towards the NE, which to me resembles a dome. This feature is poorly presented in Rukl's lunar atlas (plate 25), shown as a small mountainous peak.
Domes usually have a central top lava hole. On the peak of Mons Maraldi I noticed either of the following: (1) a small lava hole or (2) a 1-2km diameter craterlet. The setup I was using was 200mm SCT with binoviewer + 2x barlow and two 12mm plossl EPs. No moonfilter was used. Seeing conditions were good.
This small feature is included in LAC_LM Maraldi_LAC43 of the Virtual Lunar Atlas, which is denoted as gamma (right sketch). According to this chart, the elevation of this mount or dome is the same as the lava-filled floor of Maraldi - approximately 3900 ft.
The CCD image taken by P. Lazzaroti (left image) clearly defines the central hole and the dome-like feature of Mons Maraldi.
Overall this was an interesting observation. I invite astroimagers to take zoomed images of gamma Maraldi for verification.