Planetary Explorer

Ron Greeley got his start in the emerging field of planetary geology in 1967. It was no more than a decade before he successfully proposed the Galileo mission to Jupiter.

Today, the ASU professor says he can’t imagine not being a planetary geologist. Yet it was not a career that he set out to pursue. His original training was as a paleontologist.

Greeley wound up working for NASA because his ROTC college scholarship obligated him to two years in the Army. After graduate school, Greeley was assigned to Army Intelligence, where he was supposed to use his geological expertise to help interpret images. The Army trained Greeley to read aerial imagery, as well as images from infrared instruments, radar devices, and other tools of the intelligence community.

That was in the 1960s. The federal government had an abundance of projects for which it needed good geologists.

Greeley initially was scheduled to serve as geologist on the design and construction of a new Panama Canal. But before he could take the job, NASA requested that he take a position as a geologist in the Apollo lunar exploration program. Because Apollo was the top American science priority, NASA got its way. Before long, Greeley found himself looking at pictures of the lunar surface. He briefed Apollo astronauts on what to expect when they got there.

The ASU scientist’s introduction to planetary geology through a military commitment was not uncommon. But many of those whose talents NASA borrowed from the military left NASA when Project Apollo ended. Greeley stayed. He had fallen in love with planetary work.

Since Apollo, Greeley has been involved with many of the missions that have flown in solar system exploration. It’s difficult to name a mission to a rocky planet in which he didn’t participate. He analyzed data from the Mariner missions to Mars in the 1960s and early 1970s. He was part of the successful Viking orbiter and lander missions to Mars in 1976. And he also participated in the Magellan project that put an orbiter around Venus and gave us our first geological view of our sister planet.

That was just the beginning.

All told, Greeley has been chairman or member of more than 30 NASA committees, principal investigator for 17 projects, and a co-investigator or team member for nine other planetary geology projects. The ASU scientist is currently a Science Operations Working Group Chair for NASA’s Mars Exploration Rover mission.—Matthew Shindell