Charlie Duke, an astronaut on the Apollo 16 mission, didn't discover anything specifically *new* on the Moon. His mission, like the others, was focused on collecting data and samples to further our understanding of the lunar surface.

Here's a breakdown of what Duke and his crewmates achieved:

* Collected rock and soil samples: These samples provided valuable information about the Moon's geological history and composition.

* Deployed scientific instruments: They placed a variety of instruments, including a seismometer and a lunar ranging retroreflector, to study the Moon's internal structure and precise distance from Earth.

* Took stunning photographs: These images captured the beauty and vastness of the lunar landscape, contributing to our visual understanding of the Moon.

* Performed lunar rover explorations: They used the lunar rover to traverse the lunar surface, covering a significant distance and conducting geological surveys.

While they didn't make a groundbreaking discovery like finding a new mineral or ancient civilization, their mission significantly advanced our knowledge of the Moon and provided valuable data for future lunar explorations.