A new search for dark matter has turned up empty handed — but, in a silver lining, the effort provided important limits that will help future experiments narrow down the hunt for this elusive substance.
Most astronomers believe that dark matter accounts for 85 percent of all mass in the universe, and that its existence would explain the apparent extra gravity detectable around galaxies and within huge galaxy clusters. However, so far, no one has been able to identify what dark matter is made of.
