by Conor Hayes
I’ve now been with the PVL for almost five years. In that time, I’ve really come to appreciate the power of a collaboration, particularly with people outside of the lab. I first got a taste of this following the annual meeting of the Division for Planetary Sciences (DPS) in 2022. There, I was presenting some of the work that I had been doing as part of my Master’s thesis. In that work, I was examining how small-scale terrain may influence surface temperatures in the Moon’s permanently-shadowed regions (PSRs) in ways that we can’t currently observe from orbit. To do so, I was using a “Gaussian rough surface” to represent the interior of a PSR. While Gaussian roughness is a decent model for planetary surfaces over smaller regions, it’s a simplified model as it ignores larger structures like craters.
After my presentation, I got a DM on the conference’s Slack workspace from David Minton, an Associate Professor in the Department of Earth, Atmospheric, and Planetary Sciences at Purdue University. In his message, he told me that he had been developing a Cratered Terrain Evolution Model (CTEM) that can create realistic lunar terrains at small scales, and asked if I would be interested in collaborating. Over the next several months, we merged his CTEM outputs with my illumination and temperature models to create a paper that was significantly better than the version that was in my Master’s thesis.
This past February, another collaboration offered a new experience to me. During my PhD, I’ve been spending a lot of time looking at the transport of volatile molecules like water across the lunar surface. One of the more popular models for doing so assumes that molecules undergo a series of thermally-driven jumps across the surface until they are either destroyed or trapped by cold temperatures. The temperature required for one of these jumps to begin is determined by a parameter known as the “desorption activation energy.” It is arguably the most important component of the model, but its value is not well understood, particularly if you want to look at molecules other than water.
There are several ways that one can attempt to determine the value of a molecule’s activation energies, but nobody at PVL has the expertise or the equipment necessary to do so. We could just use the values in the literature while making note of their limitations, but I didn’t feel like that was the right approach. Instead, we’ve been working with Liam Morrissey and his team at Memorial University on molecular dynamics (MD) simulations of desorption, which can be used to estimate the activation energies for various molecules on different surfaces without having to put together a complex experimental setup.
As part of this collaboration, I was invited to participate in a workshop at the International Space Science Institute (ISSI) in Bern, Switzerland. This workshop was the first meeting of ISSI’s Multi-Scale Understanding of Surface-Exosphere Connections (MUSEC) International Team. At this point in my graduate career, I’ve been to many conferences, so I thought that I knew what I was getting into. It didn’t take long for my expectations to be proven entirely incorrect.
What rapidly became apparent was that a workshop is a much more collaborative environment than a conference. Rather than a rigid schedule of short talks and even shorter Q&A sessions, each presentation was more like a conversation between all the attendees. About half an hour was given to each person, not because they were expected to speak for that long, but to give ample time for discussion during and after each talk.
I had been worried because I was coming in without many actual results. Instead, the presentation I had prepared was mostly a listing of open questions that I would like to address in the final version of my model. Not exactly the kind of content that would attract much attention at a conference, but I had been assured that it was appropriate for a more informal venue such as this one. Still, I was haunted by the ever-present specter of imposter syndrome, particularly as a last-minute addition to a group of people who were already familiar with each other.
After the week’s agenda had been updated to include me, I noticed that 45 minutes had been allocated for me. Before I began, I joked that I we would definitely be taking our afternoon coffee break early, as I couldn’t imagine a world in which my set of questions could possibly consume that amount of time. As it turns out, if you start listing unanswered questions in a room full of people with the expertise to answer those questions, it inspires a lot of discussion. I was told afterwords that my presentation was exactly the kind of content that this workshop had been designed to focus on, which was very reassuring to hear given my initial uncertainty about whether I should be there at all.
Outside of the workshop itself, the MUSEC leadership made an effort to foster a sense of community with group lunch and dinner outings, which allowed everyone to get to know each other outside of our work. It didn’t take more than a day or so before I stopped feeling like an outsider. Bern itself is a beautiful city, and I hope to be able to explore it more during the next in-person MUSEC workshop next year (if writing my dissertation isn’t consuming too much of my time by then!).
