An international team of astronomers called the MACHO collaboration claim to have found fifty percent of the 'dark matter' hidden in our galaxy. They claim it could possibly be primordial black holes. However, other researchers are calling the group's interpretation of the data 'extremely controversial'. Approximately ninety percent of the mass of our Milky Way galaxy must be invisible or 'dark' to explain its rotation. Charles Alcock of the MACHO collaboration reported the findings at the "The Galactic Halo: Bright Stars and Dark Matter" meeting in Canberra, Australia, this week.