  Strangelets (hypothetical stable lumps of strange quarkmatter) of
astrophysical origin may be ultimately detected in specific cosmic ray
experiments. The initial mass distribution resulting from the possible
astrophysical production sites would be subject to reprocessing in the
interstellar medium and in the earth's atmosphere. In order to get a better
understanding of the claims for the detection of this still hypothetic state of
hadronic matter, we present a study of strangelet-nucleus interactions
including several physical processes of interest (abrasion, fusion, fission,
excitation and de-excitation of the strangelets), to address the fate of the
baryon number along the strangelet path. It is shown that, although fusion may
be important for low-energy strangelets in the interstellar medium (thus
increasing the initial baryon number A), in the earth's atmosphere the loss of
the baryon number should be the dominant process. The consequences of these
findings are briefly addressed.
