Recent Martian Meteorite: small cracks in the fragment contain bitsof black glass

Recent Martian Meteorite: small cracks in the fragment contain bits of
black glass

http://news.sciencemag.org/scienceno...eorite-fu.html

Unlike all but one other martian meteorite, however, many of the
small cracks in the fragment contain bits of black glass (the black
veins and pepperlike bits exposed on the broken surface of the
meteorite). That glass formed when material that had eroded from the
martian surface was melted by the impact that lofted material into space
about 700,000 years ago. The presence of short-lived radioactive forms
of several elements created when the meteorite was exposed to cosmic
rays during its interplanetary trek to Earth—especially vanadium-48,
which has a half-life of about 16 days—indicate that the fragments are
associated with the recent meteorite fall, the researchers say.