image by Paolo R. Lazzarotti
Squeezed between the Schiller-Zucchius basin and smaller basin Bailly, the craters Zucchius, Bettinus, Kircher and Wilson (from left to right) mark four stages on the road to ruin. Higher lighting shows that 64 km wide Zucchius has relatively crisp terraces, complex central peaks and no significant later impacts. Lunar Orbiter IV images even show secondary crater chains radiating away: Zucchius is a rather fresh impact crater. Nearby Bettinus (71 km) has lumpy terraces and the remains of a rounded peak surrounded by a smoothed floor; this guy has been modified perhaps by seismic shaking and some crater filling. Seventy-three km wide Kircher continues this trend of degradation. Its walls have little sign of terraces, lumpy or not, and the smooth floor material completely covers the peak. Wilson (70 km), the last of the nearly same sized foursome, has had its rim overlapped by craters and debris and generally is less well-defined than the other three craters. Wilson has clearly been pummelled by ejecta from the formation of the Orientale impact basin, as has Kircher and possibly Bettinus. The smooth material on the floors of these craters and in other nearly low spots could be mare type basalts lightened by bright veneers of ejecta or possibly it is fluidized (but not melted) ejecta from Orientale that filled in low spots.
Technical Details:
11 January 2006, 315 mm Dall-Kirkham Spada telescope (f/25), Lumenera Infinity 2-1M camera, Edmund Optics G filter IR blocked, 235 frames stack out of 2000.
Related Links:
Rükl charts 71 & 72
Paolo’s website
Yesterday's LPOD: Maximum Earthshine
Tomorrow's LPOD: A Widget for LPOD
