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To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.icarus.2009.05.018 Byline: Amit Levi, Morris Podolak Keywords: Trans-Neptunian objects; Kuiper belt; Atmospheres; Dynamics Abstract: In Levi and Podolak (Levi, A., Podolak, M. [in press] Icarus) we applied the theory of coronal expansion to gas escape from a small, cold, object such as those found in the Kuiper belt. Here we extend the theory to include aerosols that are lifted off the surface by the escaping gas. Aerosols carried by the gas but still gravitationally bound, tend to be lifted to a height above the surface that is dependent on the aerosol radius, so that in steady state the variation of aerosol radius with height is well-defined. We develop an extension of Parker's coronal flow theory to include the effect of aerosols carried along by the gas and use this to estimate the optical depth of such an atmosphere. For KBOs with CO evaporation from the surface and with radii in the range 245-334km, line-of-site optical depths through the atmosphere can exceed one at heights of a few hundred kilometers above the surface. Such aerosol layers should be observable, and might be used to infer the flow proprieties of the escaping gas. Author Affiliation: Department of Geophysics & Planetary Science, Tel Aviv University, Ramat Aviv, Tel Aviv 69978, Israel Article History: Received 8 October 2008; Revised 16 April 2009; Accepted 18 May 2009