How Can Strange Quark Matter Occur Deeply in the Atmosphere?
  Motivated by some recent cosmic ray experiments we study the properties of strange quark matter near flavour equilibrium. Using Fermi-gas model we argue that, contrary to some claims, the geometrical radii of quark matter strangelets are not smaller but rather comparable to those of ordinary nuclei. We propose therefore a scenario of propagation of strangelets through the atmosphere which still allows for their deep penetration. 
G.Wilk and Z.Wlodarczyk