By Nadia Drake
Scientists using Earth-based experiments to detect particles of dark matter might now know why they keep coming up empty-handed: There may be no dark matter in the solar neighborhood — at least, not within 13,000 light-years, reports a study appearing in an upcoming issue of the Astrophysical Journal.
Though dark matter, a mysterious substance different from ordinary, visible matter, supposedly makes up more than 80 percent of the matter in the universe, the new work suggests that the solar system lives in a dark matter desert. That’s a problem, because most scientists think the Milky Way galaxy is embedded in a large halo of dark matter.
If the results hold, scientists will have to reconsider what sort of shape that dark matter halo takes, although it’s unlikely to cause any major cosmological upheavals.