I have held a conversation with the second-to-last person, and only scientist, to have walked on the moon. That’s a sentence I never thought I’d write. It turns out I’m not the only member of my family that can make this claim.

On Friday, Harrison (Jack) Schmitt, who flew on Apollo 17, joined the RIS4E team at Kilbourne Hole, New Mexico. He spent the day exploring one of the sites that the team had investigated on a simulated moon walk earlier in the week. The RIS4E team members demonstrated to Jack the imaging and geochemical instruments they were testing, while he asked questions and commented on the geology of Kilbourne Hole. Picking up a volcanic rock pebble, and cracking it in two with his geology hammer, Jack joked, “we don’t need your equipment to know what this is.”

My moment to talk to Jack came half way through the morning. Noticing him standing alone, I headed over to see if he would answer a couple of questions. Kilbourne Hole is a moon analog site—the Apollo astronauts came here for geology training. I wanted to know how close the two terrains really are. Kilbourne Hole is “nothing like the moon,” said Jack, “but it was great training…we learned how to look.”

Standing with Jack Schmitt at Kilbourne Hole on June 9, 2017. (Photo: Kevin Lizarazo)

At Kilbourne hole the astronauts were schooled in spotting and collecting rock samples from diverse geological features, a key goal of the Apollo missions, and something I spent many family holidays doing with my Dad, George Thomas. Like Jack, my dad is a geologist, as was my grandfather, John Thomas.

Later that evening I emailed Dad a photograph of me standing between Jack and Butch Wilmore, an active astronaut who has lived on the International Space Station, and has been with the RIS4E team all week. I thought he would like that the hammer Jack had been carrying around all day was his father’s—my uncle, who also trained as a geologist, currently has my grandfather’s hammer.

“I met Harrison Schmitt when I was a student and he gave a talk at the Geological  Society [of London],” my Dad wrote back.  My Dad was a graduate student when Jack came to London in 1974 to talk about Apollo 17 and lunar geology. Dad was not alone when he met Jack — at his side was my grandfather.