Asteroid thermophysical modeling

TL;DR

Asteroid thermophysical modeling has advanced significantly over the past decade, enabling precise size, surface, and orbital property estimations through infrared data analysis, with implications for understanding asteroid composition, surface processes, and mission planning.

Contribution

This paper reviews recent breakthroughs in asteroid thermophysical modeling, highlighting new observational techniques and their impact on understanding asteroid surface properties and dynamics.

Findings

Thermophysical modeling confirms asteroid size estimates within a few percent.

Thermal inertia measurements reveal details about asteroid surface grain size.

Infrared data enhances understanding of non-gravitational orbital effects.

Abstract

The field of asteroid thermophysical modeling has experienced an extraordinary growth in the last ten years, as new thermal infrared data became available for hundreds of thousands of asteroids. The infrared emission of asteroids depends on the body's size, shape, albedo, thermal inertia, roughness and rotational properties. These parameters can therefore be derived by thermophysical modeling of infrared data. Thermophysical modeling led to asteroid size estimates that were confirmed at the few-percent level by later spacecraft visits. We discuss how instrumentation advances now allow mid-infrared interferometric observations as well as high-accuracy spectro-photometry, posing their own set of thermal-modeling challenges.We present major breakthroughs achieved in studies of the thermal inertia, a sensitive indicator for the nature of asteroids soils, allowing us, for instance, to determine the grain size of asteroidal regoliths. Thermal inertia also governs non-gravitational effects on asteroid orbits, requiring thermophysical modeling for precise asteroid dynamical studies. The radiative heating of asteroids, meteoroids, and comets from the Sun also governs the thermal stress in surface material; only recently has it been recognized as a significant weathering process. Asteroid space missions with thermal infrared instruments are currently undergoing study at all major space agencies. This will require a high level of sophistication of thermophysical models in order to analyze high-quality spacecraft data.