R. M. Batson E.A. Cernan V. L. Freeman M.H. Haitt H. E. Holt Keith A. Howard K.B. Jackson V.S. Larson J.J. Reed J. J. Rennilson H.H. Schmitt W.R. Muehlberger 1973 <p><span>Apollo 17 landed in a deep graben valley embaying the mountainous highlands southeast of the Serenitatis basin. Impact-generated breccias underlie the massifs adjacent to the valley, and basalt has flooded and leveled the valley floor. The dark mantle inferred from orbital photographs was not recognized as a discrete unit; the unusually thick regolith of the valley floor contains a unique high concentration of dark glass beads that may cause the low albedo of much of the surface.</span></p> application/pdf 10.1126/science.182.4113.672 en American Association for the Advancement of Science Geologic Exploration of Taurus-Littrow: Apollo 17 Landing Site article