Apollo 16 Overview

Mission Objectives

The Apollo 16 mission was the first to investigate the lunar highlands.  The scientific objectives of the Apollo 16 Mission were:

Landing Site Selection

The Apollo 11, 12, and 14 missions investigated the mare regions of the lunar surface, and ejecta from the Imbrium impact. The Apollo 16 mission was the first to explore the lunar highlands. NASA selected the Descartes landing site because its position on the edge of the Cayley Formation terra plains, adjacent to the hilly and furrowed Descartes Formation terra, made it a prime location to study the processes of highland formation. Additionally, characterizing the Descartes and Cayley Formations is essential to understanding lunar geology because these formations cover eleven percent of the lunar-near side.

Prior to the Apollo 16 mission, the aluminum-rich Descartes and Cayley Formations were interpreted as volcanic units; however, the Apollo 16 investigation revealed that features of the highlands were impact-generated. The astronauts went to Cayley looking for volcanics, but all of the rocks they found at Descartes were breccias.  These findings completely changed theories about lunar geologic processes and structure.

Surface Science

The Apollo 16 lunar surface activities were designed to reveal the formation processes of the Descartes and Cayley formations. The geologic traverses, photographs, and sample collection allowed astronauts to investigate the composition, structure, and morphology of the formations. Drive cores and deep drill core provided information about stratigraphy. The soil mechanics experiments, including the self-recording penetrometer, provided information about lunar soil properties and mechanics. The Apollo 16 passive seismometer completed a four-station seismic network and provided information about lunar structure, seismicity, and meteoroid flux. The lunar surface magnetometer experiment completed a three-station lunar network and provided information about the global lunar response to changes in solar wind magnetic field. The solar wind composition experiment revealed noble gas abundances and isotope ratios in the solar wind. The portable magnetometer provided spatial magnetic field strengths at various sites at Descartes, which could be compared to measurements from Apollo 12, 14, and 15.

Source: Apollo 16 Preliminary Science Report Mission Description