Exotic meteoritic phenomena: The Tunguska event and anomalous low   altitude fireballs -- manifestations of the mirror world?
  There are a number of very puzzling meteoritic events including (a) The Tunguska event. It is the only known example of a low altitude atmospheric explosion. It is also the largest recorded event. Remarkably no fragments or significant chemical traces have ever been recovered. (b) Anomalous low altitude fireballs which (in some cases) have been observed to hit the ground. The absence of fragments is particularly striking in these cases, but this is not the only reason they are anomalous. On the other hand, there is strong evidence that most of our galaxy is made from exotic dark material - `dark matter'. Mirror matter is one well motivated dark matter candidate, since it is dark and stable and it is required to exist if particle interactions are mirror symmetric. If mirror matter is the dark matter, then some amount must exist in our solar system. We demonstrate that the mirror matter theory allows for a simple explanation for the puzzling meteoritic events [both (a) and (b)] if they are due to mirror matter space-bodies. A direct consequence of this explanation is that mirror matter fragments should exist in (or on) the ground at various impact sites. The properties of this potentially recoverable material depend importantly on the sign of the photon-mirror photon kinetic mixing parameter, $\epsilon$. We argue that the broad characteristics of the anomalous events suggests that $\epsilon$ is probably negative. Strategies for detecting mirror matter in the ground are discussed. 
R. Foot and T. L. Yoon