Chasing Canyons Across the Solar System as Astronomer in Residence

The day I arrived at the Grand Canyon to begin my residency was cold and quiet. As I made my way to the rim, shuffling cautiously through ice patches and the occasional snowdrift, I took in a view of the canyon that few get to see: each rock layer was capped with snow, while the trail around me lay silent and still. Every day is a good day to be a planetary geologist at the Grand Canyon, because something about the canyon is different with each sunrise, but there was something very, very special about spending my weeks watching the snow slowly melt. It felt like I was there to watch the canyon reveal itself, whispering a secret into my ears through the crisp February air.

I am a planetary scientist, which means I blend astronomy and geology to understand how the features we see on Earth can apply to worlds across the Solar System, from Mercury to Pluto. More specifically, I study giant asteroid impacts, and the geologic features that are created when something big hits a planet really hard. If a giant impact happens at the right time with the right conditions, it can make canyons as deep, or deeper, than the Grand Canyon.

I’ve dedicated my life to chasing canyons across the Solar System, but it was only upon staring out across miles and miles of rock and billions of years of geologic time that I understood the scale of the features I’ve loved so much. 

Geologists call the walls of the canyon the “rock record” because that is what they are: a record, written to stand the test of time, of things that happened here. Of seas that grew and faded, lives lived and then buried deep in the sediment. Each time I stare at the canyon it’s like looking at a new page in a massive book, one that I’ve trained for years to read. Geology, much like astronomy, is the act of translation. We are reading and retelling the history of the universe as best we can, spanning distances and time periods too vast to comprehend. As a planetary scientist, it’s my job to bridge the gap between the stars and the ground, to use the geology of the Earth to tell stories about places like Pluto, where we might go only once and never see again. 

The Grand Canyon is fantastic in so many ways. For me, it showed me sides of geology and its connections across the Solar System that I had not truly understood before my visit. But it also reminds me, and so many others, about the value of wonder. At the start of my residency, one of the first questions I was asked by a park visitor was: why is your work important? How does it help us here on Earth? There’s a lot of possible answers to that question: lots of people will cite the benefits of technology invented to help explore space, like GPS satellites. Others might argue that we’re unraveling fundamental truths about the universe and why we exist in it, which is central to the human experience.  

That said, I think one glance at the canyon is enough to show us that the reason we do things like astronomy is more fundamental than that. We’ve been gazing out at places like the canyon, and up at the stars, since long before they could truly “teach” us anything. For me, being an astronomer is valuable because it reminds us to dream of worlds we might never see. It encourages us to be curious and creative about everything we find, from every faint light in the sky to every layer of rock. As I told that visitor on my first night, things do not have to be immediately useful to be worth doing. In many ways, science is a lot like art. They’re ways of probing the universe around us, but they also sustain us when nothing else can.  

As part of my time at Grand Canyon I hiked down to Phantom Ranch, where I spent as much time as I could outside, both day and night. The rocks down there are almost unbelievably old, and beautiful in their age. Each night I stood, a mile deep at the bottom of the canyon, and stared up at the stars as they were bracketed by dark rock walls. Something about it reminded me very specifically of Jimmy Carter’s message from the Golden Record, which was sent on Voyagers 1 and 2. It is a message sent intentionally out into the cosmos, to reach out to anyone and everyone, explaining what humanity is and what it might be. It reads: 

"This is a present from a small distant world, a token of our sounds, our science, our images, our music, our thoughts, and our feelings. We are attempting to survive our time so we may live into yours. We hope some day, having solved the problems we face, to join a community of galactic civilizations. This record represents our hope and our determination and our goodwill in a vast and awesome universe."

The Grand Canyon is a place where time seems to expand. When we stand on the rim, we can see billions of years into the past, which also makes me think about the future. What will the canyon become in a thousand years? What about a million? 

Out of all the things I did as an Astronomer in Residence, I am most thankful for the many, many people I met who are working very hard to steward the land, honor it, and ensure that its role as a place of wonder, as well as a sacred space to the Iindigenous peoples to whom it is home, can continue.  

We are attempting to survive our time so that we may live into yours. As I end my time at the canyon, it is my hope that all of us can carry joy and wonder with us as we go.