something connected with the stars. Orion is one of the brightest constellations as seen from Earth, and one visible to the astronauts throughout their journey. Duke also stated, "it is a prominent constellation and easy to pronounce and transmit to Mission Control". Mattingly said he chose "Casper", evoking Casper the Friendly Ghost, because "there are enough serious things in this flight, so I picked a non-serious name." Planning and training Landing site selection Apollo 16 was the second of Apollo's J missions, featuring the use of the Lunar Roving Vehicle, increased scientific capability, and three-day lunar surface stays. As Apollo 16 was the penultimate mission in the Apollo program and there was no major new hardware or procedures to test on the lunar surface, the last two missions (the other being Apollo 17) presented opportunities for astronauts to clear up some of the uncertainties in understanding the Moon's characteristics. Scientists sought information on the Moon's early history, which might be obtained from its ancient surface features, the lunar highlands. Previous Apollo expeditions, including Apollo 14 and Apollo 15, had obtained samples of pre-mare lunar material, likely thrown from the highlands by meteorite impacts. These were dated from before lava began to upwell from the Moon's interior and flood the low areas and basins. Nevertheless, no Apollo mission had actually visited the lunar highlands. Apollo 14 had visited and sampled a ridge of material ejected by the impact that created the Mare Imbrium impact basin. Likewise, Apollo 15 had also sampled material in the region of Imbrium, visiting the basin's edge. Because the Apollo 14 and Apollo 15 landing sites were closely associated with the Imbrium basin, there was still the chance that different geologic processes were prevalent in areas of the lunar highlands far from Mare Imbrium. Scientist Dan Milton, studying photographs of the highlands from Lunar Orbiter photographs, saw an area in the Descartes region of the Moon with unusually high albedo that he theorized might be due to volcanic rock; his theory quickly gained wide support. Several members of the scientific community noted that the central lunar highlands resembled regions on Earth that were created by volcanism processes and hypothesized the same might be true on the Moon. They hoped scientific output from the Apollo 16 mission would provide an answer. Some scientists advocated for a landing near the large crater, Tycho, but its distance from the lunar