In this insightful interview, we sat down with Thomas Statler, senior planetary scientist at NASA Headquarters, to highlight how asteroids can help reveal our past and protect our future. 

In his role he leads research on small bodies across the solar system within the Planetary Science Division. Thomas Statler also serves as a program scientist on key missions such as Double Asteroid Redirection Test, Lucy, and OSIRIS-APEX, supporting advances in both asteroid science and planetary defense. 

1. As we look to International Asteroid Day on 30 June, can you tell us why are asteroids so central to understanding both the origins of our solar system and the future of planetary defense?

Asteroids and comets, the “small bodies” of our solar system, are leftovers from the formation of the planets and witnesses to over four and a half billion years of solar system history. Studying their compositions helps us understand not only the objects themselves, but also the origin of our Sun, Earth, and Moon, and the other planets and moons. Their orbits, distributions, and physical properties hold clues to our own deep past and insight into the possible histories of other planetary systems. The distributions of organic molecules, water, and other volatile compounds in the small bodies can tell us how these essential materials for life formed in space, and how and when they may have been acquired by the planets. Determining the orbits and understanding the physical characteristics of objects that could potentially impact the Earth are critical for being able to respond to an actual impact threat, if one is ever discovered.

2. How are current missions helping turn asteroid science into practical strategies for protecting Earth?

Asteroid science and planetary defense both benefit from a fabulous synergy between ground-based telescopes, space-based telescopes, and destination-based space missions. The amount of information we are gaining now about asteroids throughout the solar system is growing at an unprecedented and accelerating rate; and every new mission uncovers something new and unexpected. Just one example is the almost “zero-strength” surfaces – that is, with virtually no friction or cohesion – found at Bennu by NASA’s OSIRIS-REx spacecraft and at Ryugu by JAXA’s Hayabusa2. That turned out to be very important for NASA’s Double Asteroid Redirection Test (DART) mission, which deliberately impacted Dimorphos in the world’s first test of an actual asteroid deflection technology. Dimorphos responded to the impact as a low-strength body would, which we might not have expected were it not for the earlier hints. ESA’s Hera mission will be able to examine Dimorphos up-close this autumn, to confirm and refine our understanding of exactly how the DART experiment played out, and bring us one step closer to a practical strategy for preventing asteroid impacts on Earth. But the most important step is to find the potentially hazardous asteroids, a job that is still less than half done. That is the goal for NASA’s NEO Surveyor mission, a space-based, thermal-infrared telescope being built for launch no earlier than 2028. NEO Surveyor, along with our network of ground-based observatories, will help us identify if there is any danger of Earth impact in the foreseeable future.

3. Given your vast experience as Senior Planetary Scientist at NASA, what would be your advice for the next generation of scientists?

For asteroids and other small bodies, the coming decade is going to be an amazing time of discovery. The data from NEO Surveyor, plus that from the U.S. National Science Foundation’s and Department of Energy’s Vera Rubin Observatory Legacy Survey of Time and Space (LSST), will increase the number of known small bodies across the solar system by orders of magnitude. Spacecraft will encounter and study at least 13 different asteroids close up, including the metal-rich main-belt asteroid Psyche (by NASA’s Psyche mission), eight asteroids in the Jupiter Trojan swarms (by NASA’s Lucy mission), and the near-Earth asteroid Apophis (by JAXA’s Destiny+, ESA’s RAMSES, and NASA’s OSIRIS-APEX missions). Planetary scientists should have big toolboxes, be flexible and adaptable, and be ready to dig into the data and ask the questions that nobody even knows how to ask yet.