Speaker
Description
Asteroids reflect only a small fraction of solar radiation, with the majority being emitted at thermal infrared (IR) wavelengths. This high infrared-to-visible flux ratio is especially advantageous for observing near-Earth objects (NEOs), which are often viewed at large phase angles and in close proximity to the Sun. Visible observations are hindered by straylight and rotational variations of the small, illuminated surface areas of irregularly shaped NEOs. In contrast, thermal IR observations present a different scenario:
small, fast-rotating NEOs exhibit nearly isothermal surfaces with temperatures ranging from 300 to 400 K. Consequently, the likelihood of early detection is enhanced at IR wavelengths, even at large phase angles. Additionally, IR measurements provide valuable constraints on an object's size, albedo, and thermal characteristics indicative for the strengths of the surface material.
This abstract highlights key aspects of NEO thermal IR emission measurements and their interpretation through thermophysical modeling techniques. Part of this work is based on studies conducted in the context of ESA's planned NEOMIR mission.
