ASTERIA—Asteroid Thermal Inertia Analyzer

Abstract

Thermal inertia estimates are available for a limited number of a few hundred objects, and the results are practically solely based on thermophysical modeling (TPM). We present a novel thermal inertia estimation method, the Asteroid Thermal Inertia Analyzer (ASTERIA). The core of the ASTERIA model is the Monte Carlo approach, based on the Yarkovsky drift detection. We validate our model on asteroid Bennu plus 10 well-characterized near-Earth asteroids (NEAs) for which a good estimation of the thermal inertia from TPM exists. The tests show that ASTERIA provides reliable results consistent with the literature values. The new method is independent of TPM, allowing an independent verification of the results. As the Yarkovsky effect is more pronounced in small asteroids, the noteworthy advantage of ASTERIA compared to TPM is the ability to work with smaller asteroids, for which TPM typically lacks input data. We used ASTERIA to estimate the thermal inertia of 38 NEAs, with 31 of them being sub-kilometer-sized asteroids. Twenty-nine objects in our sample are characterized as potentially hazardous asteroids. On the limitation side, ASTERIA is somewhat less accurate than TPM. The applicability of our model is limited to NEAs, as the Yarkovsky effect is yet to be detected in main-belt asteroids. However, we can expect a significant increase in high-quality measurements of the input parameters relevant to ASTERIA with upcoming surveys. This will surely increase the reliability of the results generated by ASTERIA and widen the model’s applicability.