Joseph “Joe” DeMartini is the 2024 awardee of the Schweickart Prize, for his outstanding twilight observing campaign proposal. His SUnward NEO Surveillance and Early Twilight detection (SUNSET) Collaboration proposal promises to make important contributions to the field of planetary defense by improving the detection and confirmation of NEOs during twilight hours.
Short biography – Joe DeMartini
Joe DeMartini has been working with Professor Derek Richardson at the University of Maryland since 2015, initially embarking on directed research as an undergraduate to simulate granular material (e.g., sand/gravel) dynamics on asteroids. Graduating in 2018 with a BS in Astronomy with High Honors for his proof-of-concept study for a SmallSat mission to place a seismometer on Asteroid 99942 Apophis, he remained at the University of Maryland for his Ph.D studies. His work, presented at various conferences, includes significant advancements in the realism of low-gravity granular flow simulations and our understanding of asteroid surfaces. After earning an M.Sc in 2020, he has received multiple fellowships including a Future Investigators in NASA Earth and Space Sciences and Technology 3-year Fellowship and a Chateaubriand Fellowship for combined laboratory and simulation work in France, taken at ISAE-SUPAERO in Toulouse with Dr. Naomi Murdoch. His research has been published and presented at international workshops and conferences, and he has mentored several students, highlighting his aspirations to become a university professor and his commitment to fostering the next generation of scientists.
Here, Joe shares insights into his educational background, the inspiration behind his research, and the mentors who have guided him along the way.
Can you tell us a bit about yourself? Where are you from, and what led you to pursue a career in planetary defense?
I was born and raised in Frederick, Maryland. For most of my youth, I planned to have a career as a classical musician; I would practice playing my viola for hours every week. I excelled in my early schooling, particularly in mathematics and science, so when I was not accepted to any college music programs, I decided to pursue science instead. Before I was an undergraduate, I never had any particular attachment to astronomy, but I chose it because it was, to my mind at the time, undoubtedly the coolest application of math and physics (the subjects I was good at). I started to pursue planetary defense after the professor of my first astronomy course, Professor Derek Richardson, accepted to bring me into his group for a summer research project. It was Prof. Richardson’s enthusiasm for the field and his kind mentoring approach which built up my interest and started me down the path of a career in planetary defense.
What is your educational background, and how has it influenced your research and career path?
Both of my parents have master’s degrees (and, in fact, my mother—a particularly brilliant woman—has two!), and when they told me that as a child, my response was that I would be a doctor one day, to make them proud. Even when I was studying music, I aspired to get my DMA (doctorate of musical arts)—I have always set the expectation for myself that I would get a doctoral degree. I transitioned to Astronomy when I started attending the University of Maryland as an undergraduate, graduated with High Honors in Astronomy (and a double major in physics) for my undergraduate thesis concerning the physical response of the potentially hazardous asteroid Apophis during its 2029 close approach with the Earth. I was then lucky enough to continue my studies under Prof. Richardson at the University of Maryland at the graduate level, where I have since advanced to Ph.D. candidacy and will be defending my thesis next year. I attribute most of my educational influences to a lucky string of particularly brilliant, enthusiastic, and kind mentors who were invested in my success, including Mr. William Stapp (my music tutor from my youth), Prof. Derek Richardson, and, most recently, Dr. Naomi Murdoch. I consider each of them important role models; having strong, positive support from my parents and my mentors has repeatedly brought me the confidence that I need to excel in my research and career.
Interest in Planetary Defense
What sparked your initial interest in planetary defense? Was there a particular moment or event that inspired you to focus on this field?
Just before my third year as an undergraduate, I was brought onto a mission concept to investigate whether a seismometer would be able to measure anything on the asteroid (99942) Apophis when it flies by the Earth on Friday, April 13, 2029. This was my first introduction to “planetary defense.” Apophis is an object that captures people’s interest: the proximity of its upcoming close encounter (within 6 Earth radii from our planet’s center), the size of the object (~350 meters in diameter; related to how devastating its impact would be), and its powerful name (after the Egyptian god of chaos) evoke a sense of danger or urgency that I and others latch onto. To see friends and family react strongly to the subject of my research, and to see the calm that took them when I could assure them that Apophis will miss the Earth, made me feel like I was doing something worthwhile.
The Winning Proposal
Can you explain the main focus and objectives of your winning proposal, the SUNSET Collaboration?
The focus of SUNSET is to improve the detection, discovery, and tracking of the undersampled population of Near-Earth Objects that are obscured from our view due to their proximity to the Sun in the sky. The way SUNSET hopes to achieve its goal is by creating a network of observatories capable of observing at twilight (when the Sun is just below the horizon in the evening or morning), to look as close as they can in the direction of the Sun to discover (and follow up on) small bodies in that space.
What inspired you to address the challenge of detecting Sunward Near-Earth Objects (SNEOs)?
A conversation with a close friend and collaborator, Dr. Carrie Holt, sparked the idea for SUNSET. She is a brilliant observer who, in part, studies near-sun comets. We were discussing the Chelyabinsk airburst event in 2013, and she mentioned that it was not tracked on its final approach in part because it was coming from the direction of the Sun, and was thus blotted out by the Sun’s light. When I pressed her further, she told me that there is a sizeable fraction of the sky that we do not see in a given night because we would have to point too close to the Sun, but that looking during twilight (for those telescopes that are capable) is one of the ways that observers are trying to get around this limitation. I know that IAWN (the International Asteroid Warning Network) expresses “searching, discovery, and tracking” as one of the first stages of planetary defense, and thus it struck me that SNEOs are a population where we still have significant room to improve discovery. To my mind, the core idea of SUNSET just makes sense: twilight is a time of day when other science observations are typically not taking place, and it is also a time when we can uniquely observe this particular subset of NEOs.
What makes your approach unique or innovative compared to existing methods in the field?
I believe that it is the collaborative aspect of SUNSET that makes it unique. Twilight surveys have been conducted with both ZTF (the Zwicky Transient Facility) and DECam (the Dark Energy Camera) to varying degrees, so the method is not new (although it is relatively recent at the survey scale). The issue still exists that SNEOs are highly transient objects: there is no guarantee that one telescope will be able to observe them for enough subsequent nights to generate sufficient observations to rigorously confirm the “discovery” and orbital arc of the object. With SUNSET collaborator observatories performing same-night or next-night target-of-opportunity follow-ups, then utilizing innovative, observer- and cadence-independent observation linking software (like THOR, from the B612 Foundation’s ADAM Precovery tool) for these objects, SUNSET can solve some of the challenges of SNEO discovery simply by working together!
What were some of the biggest challenges you faced while working on your proposal? How did you overcome these challenges, and what did you learn from the experience?
Perhaps the biggest challenge I faced in this process was my lack of expertise in this area of astronomy. My research focus is the design and implementation of software to simulate the dynamics of rubble pile asteroids, their surfaces, and their interiors. I have little experience in observational astronomy. Since my proposal was focused primarily on observational methods, there was a significant learning curve before I could even begin to write intelligently about my idea. I faced this learning curve in two ways: the first, as every graduate student has been taught to do, was a deep dive on the literature around twilight surveys and sunward observations. Luckily for me, the researchers who focus on these topics write very clear, descriptive publications. The second method, which I employed when I hit a roadblock in my literature review, was to reach out to the contacts that I have built during my time as a graduate student at the University of Maryland. Conversations with experts like Dr. Carrie Holt or Dr. Quanzhi Ye massively improved my comprehension of the methods utilized for twilight observations and the challenges that must be overcome. It was, as ever, on the back of personal perseverance in my studies, and, more importantly, the support and expertise of my friends and colleagues, that I was able to put together a strong proposal and win this prize.
"Each time that I find myself contributing to a success brought about by this well-oiled machine of planetary defense research and collaboration, I feel a great deal of pride, and that pride inspires me to continue my work in the field."
How do you stay motivated and inspired in a field that deals with such high-stakes challenges?
In my mind, the key to staying motivated is focusing on the task at hand. Big hurdles often seem insurmountable, but the individual successes that build to let us clear those hurdles can usually be achieved relatively easily with the appropriate effort and expertise. As such, the individual challenges that I face are within my capacity to overcome; if I find one that is not, I know that I can rely on one of the other experts in the network that I am building to help me overcome that challenge. It would be egotistical to think that the fate of the world rests solely on my shoulders; rather, we jointly share this burden of planetary defense and support each other with complementary expertise, rigorous peer review, and creative approaches to new problems. Each time that I find myself contributing to a success brought about by this well-oiled machine of planetary defense research and collaboration, I feel a great deal of pride, and that pride inspires me to continue my work in the field.
Who has been your biggest influence or mentor in your journey so far?
My primary adviser, Professor Derek Richardson, has been an incredible advocate, role model, mentor, and friend to me in the decade that we have been working together. I owe a large part of my confidence and success to the support and tutelage that he has provided at every stage of my astronomy education. His caring, teaching-focused approach to mentorship, his wide network of colleagues and collaborators, and his positive, relaxed attitude to problem-solving have been critical to my development in our field. If there is any single person to whom I owe thanks for my achievements past, present, and future, it is and will be Derek.
Future Plans
How do you plan to utilize the $10,000 prize money to further your research or career?
Going into the final year of my thesis studies, I am confronted with the need to expand my network of connections and collaborators in order to continue to make a name for myself in my field and find a postdoctoral research position. This means attending conferences and workshops, presenting my thesis research, and getting more closely involved with mission PIs and other planetary defense leaders. I plan to use this prize money, in part, to ensure that I can make it to important conferences like the 2024 Europlanet Science Congress and the 2025 Planetary Defense Conference, where I hope to present my thesis work, and possibly discuss SUNSET as well.
I am an expert on the physical effects of the 2029 close encounter between Earth and the (potentially hazardous) asteroid (99942) Apophis; I am a primary author on several publications on this topic, and it will be a major part of my Ph.D. thesis. To this end, I hope, in the coming years, to get involved with one or more of the missions or mission concepts (like OSIRIS-APEx or RAMSES) that are planning to target Apophis before, during, and/or after its close approach. I believe that the natural experiment provided by this close encounter is a golden opportunity to improve our knowledge about NEOs, and possibly to help us better characterize the surfaces and interiors of rubble piles. If SUNSET picks up serious traction as a result of this prize, then I would be excited to help build the connections and networks necessary to commence this collaboration and support the discovery of Sunward NEOs.
As Joe prepares to defend his thesis and continue his work in planetary defense, his journey serves as an inspiring example of adaptability, perseverance, and the impact of strong mentorship. The recognition from the Schweickart Prize underscores the significance of his contributions to the field. With the support of his mentors and the scientific community, Joe is poised to make even greater strides in ensuring the safety of our planet from potential asteroid impacts.