Do mirror planets exist in our solar system?

R. Foot and Z. K. Silagadze*
*Budker Institute of Nuclear Physics. 630 090 Novosibirsk, Russia.

Mirror matter is predicted to exist if parity is an unbroken symmetry of nature. Currently, there is a large amount of evidence that mirror matter actually exists coming from astrophysics and particle physics. One of the most fascinating (but speculative) possibilities is that there is a significant abundance of mirror matter within our solar system. If the mirror matter condensed to form a large body of planatary or stellar mass then there could be interesting observable effects. Indeed studies of long period comets suggest the existence of a solar companion which has escaped direct detection and is therefore a candidate for a mirror body. Nemesis, hypothetical ``death star" companion of the Sun, proposed to explain biological mass extinctions, may potentially be a mirror star. We examine the prospects for detecting these objects if they do indeed exist and are made of mirror matter. The possible connection of these ideas to the Tunguska phenomenon was indicated by Foot and Gninenko: if the photon-mirror photon mixing parameter is big enough, mirror meteoroids would effectively interact with Earth's atmosphere, releasing most of their kinetic energy in the atmosphere and possibly ending in atmospheric explosion. In such ``Tunguska-like''events neither meteoroid fragments nor any significant crater would be found.