November 22, 2008
A Dome On the Limb
iimage by Damian Peach
This is an update of a classic LPOD from Jan 7, 2007 - can you spot the change?.
Far out on the Moon’s southeast limb is Mare Australe, a rimless collection of mare-filled craters and mare patches that are all that’s left of an ancient impact basin. The features in Australe are too squashed by foreshortening to be well studied from Earth, until now. Damian has captured a remarkable high resolution, low-Sun view of Lyot, the largest crater within Australe. A relatively high-Sun Kaguya image shows that the northwestern quadrant of Lyot is dark mare and the rest is older and perhaps dusted by highland ejecta. On Damian’s image this difference is indicated by the greater number of craters and greater roughness of the southern part of the floor. A few mare ridges and a ghost crater are visible on the floor, but most interestingly - and apparently unknown - is the large dome at the northern end of the floor. Its diameter is 13 km - scaled from the 38 km length of Lyot A, the bright crater at upper left. The existence of this dome is interesting because Australe, despite its abundance of mare has few small volcanic eruption landforms such as domes, sinuous rilles and volcanic dark halo craters. But while researching this dome I discovered one more and a swell on another part of Australe!
6 November, 2006. C14 @ F25. Lumenera Skynyx 2.0M.
Rükl plate 76
Yesterday's LPOD: A Rim
Tomorrow's LPOD: Moment of Impact