His decision was based in large part on the geology field training that he had received from geologist Leon Silver of Caltech. The moment was dramatized in Tom Hanks' incredible HBO mini-series From the Earth to the Moon:
"...but from what I've learned out in the field; Hadley Apennine, with it's complex variety of features, both impact and volcanic, is the best choice for putting together a picture of how the moon came to be. Maybe a little riskier...but... also the Apennines have something else... Grandeur. And I believe there's something to be said for... exploring beautiful places... It's good for the spirit."