AbstractLaboratory tests that were supplemented by a new numerical model have been conducted to study mechanical properties of asteroids with a highly heterogeneous structure. The functional form of the method of molecular dynamics, which was extended to macroscopic spatial scales, has been used in the numerical model. In the experiment, targets that were composed of glass balls, which were bonded by conventional ice, interacted with fast impactors. High-speed cameras recorded the destruction process of the ice matrix and preservation of glass balls without damage. In parallel, parameterization of the mathematical model was performed and calculated data have been compared with the experiment. The energy range of impactors when the impact causes deflection of the target with minimal destruction was able to be determined.

As time progresses, satellites launched into the GEO region have gotten smaller, and smaller, making the ability to detect and track decimeter-sized targets at these distances increasingly difficult but important for determining operational status, revealing changes, identifying, and characterizing. Previously we demonstrated that by using the Magdalena Ridge Observatory’s (MRO’s) 2.4-meter telescope, we could detect debris and other objects in GEO at visible magnitudes as faint as V~20 or fainter in single images, and were able to derive reliable and accurate astrometry. We also established that employing strategic shifting and summing of individual images based on the anticipated motion of the target allows for this magnitude limit to be extended somewhat. Initially, since objects in geostationary orbit typically move about 15 arc-seconds per second with respect to sidereal motion, we limited exposure times to half a second or less to avoid significant trailing and analyzed the photometric signatures using circular apertures. For this current work, we explore techniques using elliptical apertures and extend individual exposures to push our detection limits to V~21 visible magnitude and fainter. We investigate the limitations in accuracy inherent in this approach and examine the relative practicalities of utilizing longer individual integration times versus the software shifting and summing of shorter exposures. We also explore the magnitude, and hence size, limitations that these techniques imply for the characterization of artificial objects when studying their temporal photometric and spectroscopic signatures.

Laboratory tests that were supplemented by a new numerical model have been conducted to study mechanical properties of asteroids with a highly heterogeneous structure. The functional form of the method of molecular dynamics, which was extended to macroscopic spatial scales, has been used in the numerical model. In the experiment, targets that were composed of glass balls, which were bonded by conventional ice, interacted with fast impactors. High-speed cameras recorded the destruction process of the ice matrix and preservation of glass balls without damage. In parallel, parameterization of the mathematical model was performed and calculated data have been compared with the experiment. The energy range of impactors when the impact causes deflection of the target with minimal destruction was able to be determined.