Shapes and Spins of Near-Earth Asteroids
<p>Asteroids are diverse and numerous solar system objects, from the large number of objects in the main asteroid belt to the relatively small near-Earth population. Understanding their physical properties is essential to understanding the evolution of the solar system, and asteroid morpholog...
| Summary: | <p>Asteroids are diverse and numerous solar system objects, from the large number of objects in the main asteroid belt to the relatively small near-Earth population. Understanding their physical properties is essential to understanding the evolution of the solar system, and asteroid morphology is a complex field in its own right. The histories of individual asteroids, and particularly near-Earth objects, reflect continuous interaction among their shapes, rotation states, and orbits due to the effects of radiation pressure.</p>
<p>Radar astronomy has provided detailed information on the orbits, sizes, shapes, rotation states, and composition of many asteroids. To improve the capabilities of asteroid radar observations, I have developed the technique of radar speckle tracking. The echoes from different points on the surface of a radar target interfere with each other, producing a pattern of bright and dark speckles across the surface of the Earth. Using radio astronomy techniques, I track the motion of speckles between several ground stations during a radar experiment to accurately determine the rotation state of the target. Speckle tracking is a powerful tool to both determine the orbital evolution of near-Earth asteroids, particularly potential Earth impactors, and to survey the overall physical properties of the asteroid population.</p>
<p>In addition, I have studied applying the techniques of adaptive optics and radio interferometry to asteroid science. These will become more useful with the next generation of asteroid-detecting surveys and the construction of large sub-millimeter interferometers. Interferometry in particular will soon be able to survey the entire asteroid belt.</p>
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