Near-surface stratigraphy in comets inferred from observation,laboratory studies,and modeling

A brief discussion is given of the physical processes that may lead to a differentiation of the nucleus of short period comets. It is concluded that samples from the near-surface layers of such comets may give us important information on the initial state of cometary organics and refractories. Cometary ices are more likely to be indicators of the recent evolution of the comet.     

Noise, Radar Moving-Window Detectors, and False Returns

Moving-window false report probability is shown to overestimate effects of noise. "False-report-start" probability is calculated and compared to the usual false report probability. The ratio of the two exceeds a simple function of window length, threshold, and noise probability, which is tabulated for some representative values.