WEIGHING NEUTRINOS WITH GALAXY SURVEYS. Unlike recent neutrino oscillation experiments (which measure the mass difference between neutrino species: Update 375), cosmological measurements might be able to probe neutrino mass directly. This is because the teeming neutrinos in the universe would, with even a pinch of mass, play an important shepherding role in the behavior of galaxies: heavier neutrinos (through their gravitational exertions) would tend to suppress galaxy clustering. Scientists at the Institute for Advanced Study (Daniel Eisenstein, 609-734-8013, eisenstein@ias.edu) have proposed a way in which accurate maps of galaxies (such as will be furnished by the Sloan Digital Sky Survey) and accurate maps of the cosmic microwave background (such as will be provided by the Microwave Anisotropy Probe) can be combined to yield the neutrino mass if it exceeds about 1 eV. (Hu, Eisenstein, and Tegmark, Physical Review Letters, 15 June 1998.)