Image by NASA
In old cabinet drawers and aluminum boxes, Eugene Shoemaker kept his growing collection of minerals. His father took him traveling around Wyoming, where he picked up all kinds of rocks to bring back home. In 5th grade, Gene enrolled at the Buffalo Museum of Science in evening high school level science classes. There was no doubt that he was a science kid.
Shoemaker was born in Los Angeles in 1928 and moved back and forth between there and Buffalo a few times. But at a very early age, he was absolutely enamored with rocks. By nine he was a collector and regularly read geology textbooks. However, despite his enthusiasm, he had no idea how great a scientist he would grow up to be.
After college, he wanted to be a field geologist
Shoemaker finished high school in three years and went right to college at the California Institute of Technology, in 1944. Unfortunately, the geology department was basically shut down for World War II, because many of the geologists were working for the Defense Minerals Program, looking for critical mineral deposits in the U.S.
Gene ended up taking all his geology classes in his last year when the professors came back. After getting his Bachelor’s and Master’s at Caltech, he took a job with the United States Geological Survey. At this point, Gene knew he wanted to be a field geologist, but he didn’t know yet how far that would take him.
Gene was determined to get to the Moon
The nuclear events of World War II left Shoemaker thinking hard about the near future of scientific innovation. He was optimistic. He believed great scientific advancements would happen in his lifetime, including in-person moon exploration. And, in his mind, who better to explore the Moon than a geologist?
“I made up my mind right then and there, I’d be standing at the head of the line, use whatever opportunities came along to be as near as I could to being the most qualified geologist to go to the Moon,” Gene said in an interview for the American Institute of Physics.
For now, though, there wasn’t much Gene could do to get to the Moon. So he focused on his job with the U.S. Geological Survey and did graduate studies at Princeton, while reading lunar research papers on the side. He didn’t tell many people of his secret ambition, but instead worked toward becoming the most qualified field geologist for any future lunar missions.
Gene was very interested in geologic mapping, which is the process of mapping the different kinds of rocks and sediments in an area. It took him to the Hopi Buttes volcanic field in Arizona. The field was full of craters that, to Gene, looked rather like the Moon’s craters. This lead him toward one of his biggest contributions to scientific understanding.
Scientists thought craters were made from volcanic eruptions but Gene had a different idea
At the time, scientists believed craters on Earth and on the Moon were made from explosive volcanic eruptions, but Shoemaker thought otherwise. He got a clue toward the real crater-maker while exploring old volcano vents as part of his job with the Geological Survey.
He was actually looking for uranium but was more interested in the structures left behind by the volcanoes. Following this research, he was sent to old nuclear test sites because the Atomic Energy Commission thought doing underground nuclear explosions would make more plutonium. But to ensure it wouldn’t create an eruption on a volcanic scale, they sent Gene on a classified mission.
Gene’s work took him to Meteor Crater, which led him to a scientific breakthrough
Shoemaker compared the nuclear test sites to the volcanic field and realized there’s a difference between holes made from erupting out of the inside of the Earth versus hitting into the surface from the outside. With this information, he was headed toward the scientific discoveries that distinguished his career.
Not long after, the need for plutonium passed, so they never carried out the explosions. But this research led Gene to something new: Meteor Crater. The crater is almost a mile across and about 550 feet deep, situated in the middle of Arizona. It’s been there as long as anyone can remember. Gene believed it was made by a celestial rock hitting the Earth and that the craters on the Moon were made the same way.
Gene tried to start a lunar geology project before we even sent anything to space
Gene felt the scientific tide shifting and believed that space exploration was coming soon. So, before any satellites were even shot into space, he went to the head of the Geological Survey to plant some seeds for a future moon project. He wanted to use telescopes to start mapping the Moon’s geology.
After several years of having a secret ambition to get to the Moon, Gene finally revealed his interests and started to push them forward. He knew that someone would step on the Moon in his lifetime, and hoped it would be him, but he never imagined how soon it would happen.
The Soviets launched the first satellite into space, pushing Gene to act fast
In 1957, the Soviet Union shot the proverbial starting pistol for the space race, by launching Sputnik 1, the first artificial satellite, into space. When Gene heard this, he thought, “Oh no! I’m not ready yet! It’s too soon.” He had started pursuing his Moon ambitions, but hadn’t yet finished the volcanic work he was doing.
NASA wasn’t even founded until the next year, but an informal group started around the question of how could we possibly get to the Moon. They brainstormed the math and science it would take to get someone on its rocky surface. And Gene, of course, was part of that group.
Soon enough, Gene and a few other members of the Geological Survey had a meeting for anyone interested in getting into lunar research. Together, they came up with a research program proposal and sent it to the new chief geologist, hoping to work on it over at the newly formed NASA.
Well, the chief geologist wasn’t particularly interested in their lunar proposal and had a lot of other work distracting him. “So at this point, I was starting to look around, because I didn’t know whether the Geological Survey was going to go to the Moon but I was determined that Gene Shoemaker was,” Gene said.
Gene was the first to map the geology of the Moon
Gene took matters into his own hands and, using telescopic photographs and a topographic map of the Moon, he drew up the first geological maps of the Moon. He was forcing his way to become a foremost lunar geologist and was even invited to give a talk about it in Washington D.C.
At the event, Gene got drunk at dinner and gave “one of the best talks, most important talks I ever gave in my life.” He talked about the Copernicus crater on the Moon and, fortunately, the very influential John O’Keafe was in the audience. O’Keafe helped Gene finally get the lunar mapping project up and running.
Meteor Crater gave Gene the evidence he needed for his impact theory
So Gene and a few other geologists worked on lunar mapping, but most geologists were not taking their project very seriously. They didn’t believe NASA would send a spacecraft to the Moon. To them, Gene just had his head in the stars and he’d never get his feet on the Moon.
Around the same time, Gene finally finished his Ph.D. thesis on Meteor Crater. And not long after, he and a small team discovered the first natural occurrence of a mineral called coesite, at Meteor Crater. Finally, here was the evidence to support Gene’s theory that a meteorite impact caused the crater formation.
Coesite is a form of quartz that is made from very high pressure and high temperatures, which are only high enough on the Earth’s crust when a meteorite impacts the ground. So here was the evidence to counteract the volcanic crater-creation theory. Around 1960, Gene went to Germany and found coesite at other craters there, including the 15-mile-across Ries crater.
“That was a big breakthrough, because this was the first demonstration that indeed there are very large structures on the Earth produced by impact, structures very much larger than Meteor Crater, and of course this provided a very important link in identifying craters on the Moon as of impact origin,” Gene said.
With his geological maps of the Moon, Gene was trying to understand its history. He thought its craters were created over a large span of time, by celestial bombardment. He and his team of lunar geologists did experiments in Meteor Crater to study the impact theory and at night they conducted telescope observations at the Lowell Observatory, 40 miles away in Flagstaff, Arizona.
Around this time, 1961 to 1963, the first American astronauts (the Mercury Seven) were going into space. They were all military test pilots and most got to orbit Earth. No one with a science background had been selected to go to space, yet.
Gene’s hopes of being the first to go to the Moon were dashed
But in 1962, Gene realized he wouldn’t be among the first men on the Moon. There hadn’t been any scientist-astronauts yet, and he figured NASA would choose test pilots rather than geologists for the Moon mission. Over the summer, he was at a Space Science Board meeting when two guys came and confirmed his grim prediction.
“There were a couple of guys that came up from Iowa City and they told us how it was going to be two astronauts,” Gene said. “It was perfectly plain that they didn’t want scientists sticking their damn noses in any way into the whole venture. They regarded us as a huge nuisance. It was offensive.”
In the Fall, Gene went to Washington to advocate for scientist-astronauts. Maybe scientists wouldn’t be in the first Apollo missions, but he was determined to get some scientist (preferably himself) to the Moon. But his chances of a trip to space soon collapsed.
Gene started to feel unwell. His blood pressure was low and he was anemic. “I started losing weight. I was scrawny … By Spring it was getting really serious. I would go home and just collapse on the couch. I just didn’t have enough energy to do anything. I’d just get up the next morning; physically it was a really difficult period,” he said.
He found out there was no way he could be an astronaut, and so there was no way he could go to the Moon
Over the next several months, Gene’s condition only got worse. But the doctors couldn’t diagnose it. “I started losing control of my speech. I couldn’t fully bend my knees; my joints were getting stiff. I would get uncontrollable spasms of hiccups,” he said.
As the symptoms piled up, the doctors realized it was his adrenal gland. He had Addison’s disease. “If I hadn’t found out what it was I had a year left to live,” he said. But while they caught it in time to save his life, he now knew there was no way he could ever pass the physical to be an astronaut. Out of all the sickness he’d gone through, Gene said, “that was the cruelest blow.”
Gene had a new mission: make geology a priority for the Apollo missions
If Gene couldn’t be the geologist to go to the Moon, then he had a new mission: make sure the astronauts going actually know a thing or two about geology. He wanted them to be able to properly observe and collect samples of the lunar surface. But the problem, he realized, was that it’s impossible to teach field geology because you have to learn it by actually doing it.
Gene had experience teaching field geology to students at Caltech, where he took them on weekend field trips to make sure they actually learned how to do the work. So Gene pushed to make geology a priority for the Apollo missions. “This was what going to the Moon in my book was all about,” he said. “Why do you send a man up there? What’s he going to do — discover what’s there.”
He also worked on other space missions, like Ranger and Surveyor
In the meantime, Gene was still involved in the current space missions. He worked on the Ranger 7, 8, and 9 missions, which were the first spacecrafts to get a close look at the Moon’s surface in 1964. They took pictures that were far better than anything a telescope could get.
Gene was also the Principal Investigator for the television camera on Surveyor, which was the first U.S. spacecraft to actually safely land on the Moon. The Surveyor missions took pictures of the lunar surface, so scientists could determine if the ground was safe for a manned spacecraft to land. Plus, the Surveyors did some chemical analysis of the Moon’s surface.
Gene trained the Apollo astronauts on how to do field geology
Around this time, NASA was preparing the Apollo missions that would send the first people to the Moon. Shoemaker helped train the astronauts in Meteor Crater, Arizona. They set up a mock landing site to let the astronauts practice making geological field observations because Gene knew the only way to learn was to practice.
The Apollo Program got six different missions to the Moon. Gene even helped select scientist-astronauts for NASA, once they decided to actually get scientists up in space. While Gene did help get scientists to the Moon, he was now watching as they blasted off instead of him.
Gene picked a geologist to go to the Moon with Apollo 17
In a bittersweet twist of fate, Shoemaker selected the geologist Harrison Schmitt to go on Apollo 17. Schmitt had worked for the USGS and with Gene on lunar mapping and astronaut training in Arizona. So a geologist was going to the Moon, but it wasn’t Gene.
“It’s kind of an ironic turn of events,” Gene said, “because way back in 1948 I had imagined that there would be some point in time in which the National Academy of Sciences would be asked to review the qualifications of scientists who wanted to go to the Moon, and my goal then had been to be standing at the head of the line as an applicant. I never pictured that I would end up chairing the committee to review the applicants.”
The Apollo missions were a huge disappointment to Gene
Unfortunately, Apollo never achieved what Gene thought it could. NASA planned every step, not allowing for new observations to guide the astronauts’ steps. To be a real field mission, Gene said, the astronauts needed to be able to go make observations wherever they saw something interesting. To him, the missions were a lost opportunity.
“My dream for Apollo,” Shoemaker explained, “was to try to create the opportunity to show what a well-trained human being could do on the spot. This is not a kind of science that most scientists understand, because they don’t do it. And in the six moon landings, we never demonstrated that important discoveries could be made from field observations.”
Gene trained astronauts for the first three Apollo missions, but at some point, he had to move on. “The Moon’s been waiting for me — I’m not going to make it,” he said. Gene turned his gaze from the Moon to something else in the sky: comets.
After discovering how the meteors on Earth and the Moon were created, Gene became concerned about when Earth would be hit again. He worked on a program to track comets (which are made of ice and dust) and asteroids (which are made of rock) as they flew through the sky. He, his wife Carolyn, and another scientist discovered the comet that struck Jupiter in 1994.
Not going to the Moon was Gene’s biggest disappointment
The comet that fell into Jupiter was named the Shoemaker-Levy 9 Comet and it was the first time people observed a planetary collision. Jupiter’s gravity ripped apart the comet, which fell into the planet and created quite a fireworks show. Before long, Gene and Carolyn held the world record for the most comets discovered, at 32 comets.
”Not going to the Moon and banging on it with my own hammer has been the biggest disappointment in life,” Gene told Sky and Telescope last year. ”But then, I probably wouldn’t have gone to Palomar Observatory to take some 25,000 films of the night sky with Carolyn, and we wouldn’t have had the thrills of finding those funny things that go bump in the night.”
At age 69, Gene Shoemaker’s dreams of exploring the lunar surface came to an abrupt end. It was 1997 and he was investigating meteorite craters in Australia with his wife. It wasn’t his first time there, as he had earlier remarked that he and his wife “have a whee of a time just poking around those old holes in the ground.”
But a head-on collision tragically ended Gene’s ventures on Earth. He died in the car crash and Carolyn was hospitalized. But unbeknownst to Gene, his death was not the end of his journey to the Moon. Even though he had passed away, one person still had hope that he could get there.
Gene’s friend realized this was the last chance to get him to the Moon
Gene’s death was the end of a long and successful scientific career, but despite its length and his many contributions to science, there were probably future insights lost with Gene. Just a month earlier, he’d shaken planetary science again, with the realization that the asteroid Mathilde was made of sand.
His former student, colleague, and friend Carolyn Porco was there when he solved the sandy asteroid problem and she was amazed at his brilliance. So when she learned he would be cremated, she immediately thought about how sincerely he had wanted to go to the moon. She thought, “Let’s send Gene to the moon. This is his last chance.”
Carolyn Porco quickly set forth a plan to get Gene to the moon. She emailed everyone she could think of that might be able to help, and even though it was Saturday, she got all her questions answered within a day or two. She needed to know when the next lunar mission would be launched and whether or not there was room for a small capsule on it.
Lunar Prospector, an unmanned spacecraft, was set to launch the next year to map the Moon’s surface. It was going to look for polar ice, measure magnetic and gravity fields, and study gasses coming out of the lunar surface. This spacecraft was Gene’s last hope at getting to the Moon.
NASA agreed with the plan and liked “the poetry of it”
Gene’s wife told Porco she would be forever grateful if she could get his ashes to the Moon. And all Porco needed to get him there was a small unoccupied space on the Lunar Prospector to put a capsule of his ashes. But it was late in the space launch planning and the Prospector was in the final testing stages already.
Luckily, Scott Hubbard, the Lunar Prospector mission manager, was open to the idea. And nine days later, NASA’s Associate Administrator for Space Science Wesley Huntress told Porco, “I like that idea, Carolyn. I like the poetry of it.” After all that Gene had done for NASA, they were now going to help him fulfill his final mission.
NASA ended up calling the company Celestis to help them. Earlier in the year, Celestis had completed their first space mission: launching the ashes of 24 people into space on the “Founder’s Flight.” Their whole business was memorial spaceflights, because who doesn’t want their ashes blasted into space?
They work by finding extra room on already planned space launches and filling them with people’s ashes, which are contained in capsules and then attached to some sort of equipment. Usually, the ashes, and the equipment they’re attached to, end up orbiting Earth. Celestis decided to help Porco and NASA get Gene’s ashes on the Lunar Prospector.
Well, there wasn’t much time to make the whole trip to the Moon happen, so Porco did a bit of scrambling and driving around. In August 1997, she drove to Phoenix (from Tucson) and got a piece of brass foil laser-etched with Eugene Shoemaker’s name, a picture of the Hale-Bopp comet (the last comet he saw with his wife), a picture of Meteor Crater, and a passage from “Romeo and Juliet.”
The next day she drove a few hours north to Flagstaff, Arizona. At Shoemaker’s house, she had a ceremony with his family and they put an ounce of his ashes in the capsule and wrapped it with the foil. Then Porco drove back to Phoenix to fly to the Ames Research Center in California. Finally, she delivered the little package to Scott Hubbard.
At long last, Gene went to the Moon
A few months later, on January 6, 1998, Lunar Prospector was launched to the Moon. For over a year, it had sampled and mapped, until it finally completed its mission. NASA purposefully crashed the Prospector on the Moon on July 31, 1999, taking Gene’s ashes with it. Finally, he had gotten to the Moon.
While 12 people have walked on the Moon, only one person has ever been buried on it: lunar geologist and planetary scientist Gene Shoemaker. After a career studying celestial collisions, Gene became one himself when he crash-landed on the lunar surface. Hopefully, his foresight will save us from any future comets or asteroids straying too close to Earth, but it’s a shame he’ll never see us get to Mars.
Quotes were used with permission from the American Institute of Physics:
Interview of Eugene Shoemaker by Ron Doel on 1986 January 30, Niels Bohr Library & Archives, American Institute of Physics,
College Park, MD USA, www.aip.org/history-