Looking Across Orientale

Looking Across Orientale

I can never get too much of Orientale. True, the wonderful Lunar Orbiter image shows it more fully and at higher resolution than we see from Earth, but I love looking across Mare Orientale and observing the Rook Mountains sticking into the black lunar sky. Ninety degrees west longitude occurs at the crater Kopff (mouseover), and Paolo’s great image – taken this January when the librations were especially favorable – shows both the nearside and the farside (about 110 degrees longitude) arcs of the Inner Rooks. The distant profiles reveal these basin ring mountains to have considerable slopes, and while most are bulbous, some are pyramidal. Notice the monotonous hue and relatively featureless surface outside the Cordillera and indeed outside the Outer Rook Mountains. The material outside the Cordillera is thick ejecta deposits that bury the diversity of the pre-Orientale topography. But the area between the Outer Rook and the Cordillera has the same bland nature – it appears to also be ejecta, but lacking the radial ridges and furrows.