• comet impact;
  • thermospheric dynamics;
  • two-dimensional turbulence

[1] During two solstices, Stevens et al. [2003, 2005] presented satellite and ground-based observations that indicated that the water vapor plume from the space shuttle's main engine rapidly expanded and moved quickly to the summer pole. Once there, the water vapor plume condensed into large noctilucent cloud displays. Here we present a hypothesis for the plume's rapid transport and anomalous horizontal diffusion. We argue that this system is two-dimensionally turbulent, which has the property of inverse cascade. This energy transport to large scales explains the poleward transport, and the well-known system properties explain the anomalous diffusion. Additionally, we apply these results to the aftermath of the 1908 Great Siberian Impact Event, when extremely bright night skies were observed in Great Britain during the days following the impact. The impacting object must have contained considerable ice and thus, was very likely a comet.