SLAC cosmologists are using multiple images of the same quasars, produced by massive galaxies’ gravitational pull, to calibrate cosmic distances. Their work may help resolve long-standing debates about how quickly the universe is expanding.

Observations of dwarf galaxies around the Milky Way have yielded simultaneous constraints on three popular theories of dark matter.

Physicists at SLAC and Stanford propose that the influence of cosmic rays on early life may explain nature’s preference for a uniform “handedness” among biology’s critical molecules.

Just like we orbit the sun and the moon orbits us, the Milky Way has satellite galaxies with their own satellites. Drawing from data on those galactic neighbors, a new model suggests the Milky Way should have an additional 100 or so very faint satellite galaxies awaiting discovery.