By Ron Cowen
Astronomers have discovered a billion light-year–long region devoid of matter, the biggest hole in the cosmos they’ve yet observed.
A void this large hadn’t been predicted by the leading model of cosmic evolution, says Lawrence Rudnick of the University of Minnesota in Minneapolis. He and his colleagues base their new findings on a radio-wavelength survey of 82 percent of the sky using the Very Large Array in Socorro, N.M. The dearth of galaxies lies in the constellation Eridanus, the team reports in an upcoming Astrophysical Journal.