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Momentous Discoveries: Impacts and Gene Shoemaker

Gene Shoemaker with Rocket Belt

Gene Shoemaker with Rocket Belt

Accretionary Wedge #60 is all about Momentous Discoveries in Earth Science

Even before the Apollo missions. Eugene Merle Shoemaker wanted to go to the moon. A geologist by training, he figured that it was only logical-if we were going to go explore the surface of another world, shouldn’t you send someone who understood how this world worked?

Shoemaker’s most lasting and momentous discovery was his realization that impacts from asteroids could alter landscapes on large, unimaginable scales. After witnessing the craters created during nuclear testing, he started taking a closer look at craters like the Barringer and Ries. He found that both the natural craters and the craters born by nuclear explosions contained a peculiar form of quartz, that he’d never seen before. Along with fellow researcher Ed Chao, Shoemaker figured out that this form of quartz, which they called coesite, could only be formed in environments of incredibly high heat and pressure, far higher than could ever be found on earth under normal circumstances. Shoemaker believed that this was proof that these crater formations were caused by impacts from asteroids, not volcanoes as previously believed.

Around the same time, Shoemaker founded the Astrogeology Research program of the USGS in 1961, and hoped to be among the first to study the geology of the moon, but sadly, in 1963 he was diagnosed with Addison’s disease, a condition that eliminated him from the list of potential astronauts.¬†Undaunted, Shoemaker continued his work, training other potential astronauts how to collect samples from the moon, working with them in on simulated lunar surfaces in the American West, and chatting with Walter Cronkite before Apollo launches.

Shoemaker’s impact theory was eventually fully accepted in 1994, when a comet (Shoemaker-Levy 9) discovered by himself, his wife Carolyn and their fellow researcher David Levy slammed into Jupiter. This was the first large impact ever directly observed, and the images of the massive dark spot where the comet hit were enough to terrify millions of people around the world. The event inspired Congress to direct NASA to find planet-threatening asteroids, and spawned movies like Armageddon and Deep Impact. Without Shoemaker’s discovery, it would have taken us a lot longer to even start looking for the kinds of large asteroids that could pose a threat to our continued existence here on earth.

Shoemaker finally got to the moon in 1999, two years after he died in a car crash in Australia. A vial of his ashes were sent into space aboard the Lunar Prospector, which slammed into the moon’s surface. He is the only person to have his remains interred on another celestial body. Though the vial was likely destroyed on impact, it was originally inscribed with this quote from Romeo and Juliet:

“And, when he shall die,

Take him and cut him out in little stars,

And he will make the face of heaven so fine

That all the world will be in love with night,

And pay no worship to the garish sun.”