Shining Light on Thermophysical Near-Earth Asteroid Modeling Efforts

Comprehensive thermophysical analyses of Near-Earth Asteroids (NEAs) provide important information about their physical properties, including visible albedo, diameter, composition and thermal inertia. These details are integral to defining asteroid taxonomy and understanding how they interact with the solar system. Since infrared (IR) asteroid observations are not widely available, thermophysical modeling techniques have become valuable in simulating properties of different asteroid types. Several basic models that assume a spherical asteroid shape have been used extensively within the research community. As part of a program focused on developing a simulation of space-based IR sensors for asteroid search, the Near Earth Asteroid Model (NEATM), was selected. This review provides a full derivation of the formulae behind NEATM, including the spectral flux density equation, consideration of the solar phase angle, and the geometry of the asteroid, earth, and sun system. It describes how to implement the model into software and explores the use of an ellipsoidal asteroid shape. It also applies the model to several asteroids observed by NASA’s Near-Earth Object Wide-field Survey Explorer (NEOWISE) and compares the model’s performance to the actual observations.

DISTRIBUTION STATEMENT A. Approved for public release. Distribution is unlimited.

This material is based upon work supported by the National Aeronautics and Space Administration under Air Force Contract No. FA8702-15-D-0001. Any opinions, findings, conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Aeronautics and Space Administration .