It's important to remember that many astronauts involved in the Apollo missions had scientific backgrounds and contributed to scientific research. However, there isn't a single "true scientist" who can be definitively said to be the only one to walk on the moon.

Here's why:

* Diverse Fields: While astronauts like Harrison Schmitt had a background in geology, others had training in engineering, physics, or medicine. Each field contributes to scientific understanding.

* Collaborative Research: Space exploration is a collaborative effort. Astronauts gathered data, conducted experiments, and brought back samples, all of which contributed to scientific knowledge.

* Scientific Expertise vs. Astronaut Training: Astronaut training is crucial for spaceflight, but it doesn't necessarily limit someone from having a strong scientific background.

Instead of focusing on a single individual, it's more accurate to recognize the collective scientific contributions of all the Apollo astronauts. They all played a part in advancing our understanding of the moon and space.