  I argue that cosmic Gamma-ray Bursts (GRB) may be produced by collapses or
mergers of stars made of `mirror' matter. The mirror neutrinos (which are
sterile for our matter) produced at these events can oscillate into ordinary
neutrinos. The annihilations or decays of the latter create an
electron-positron plasma and subsequent relativistic fireball with a very low
baryon load needed for GRBs. The concept of mirror matter is able to explain
several key problems of modern astrophysics: neutrino anomalies, the missing
mass, MACHO microlensing events and GRBs. Thus this concept becomes very
appealing and should be considered quite seriously and attentively.
