Saturday, April 16, 2011

LOLA's Deep Antoniadi

LOLA Featured Image: Antoniadi Crater (69.7S, 188E); bounding (79S, 177-197E; 66S, 180-195E - 135 km), flanked by two smaller, older craters, Minnaert (l) and Numerov (r), is a transitional crater, exhibiting both a central peak characteristic of complex craters and inner ring characteristic of larger multi-ring basins. The deepest point on the Moon (-9.12 km) is measured inside Antoniadi. (Topographic data from LOLA is being used to measure the depth-to-diameter ratio of transitional craters like Antoniadi with higher precision than ever, in hope of better understanding the formation of different types of large impact structures [Sori & Zuber (2010). Preliminary Measurement of Depth-to-Diameter Ratios of Lunar Craters in the Transition Regime between Complex Craters and Multiringed Basins. 41st Lunar & Planetary Science Conference, #2202].

Antoniadi, prominent feature of the southern farside (69.7°S, 188°E), well to the interior of the ancient four billion-year-old South Pole-Aitken (SPA) impact, is host to the Moon's lowest elevations. The 11 km crater at lower center, without, as yet, any official name, formed the Moon's deepest point, measured by laser reflection from Japan's Kaguya orbiter at 9.06 km below the global mean elevation. Rewarding Challenge: find Antoniadi where we found this LROC Wide Angle Camera (WAC) monochrome mosaic, by zooming in on the southern polar stereographic projection using the LROC WAC Mosaic Viewer. (Hint: the view above is rotated, showing the farside with the north at top [NASA/GSFC/Arizona State University].

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