Astronomers have discovered a clump of 73 quasars that spans four billion light years at its widest point--that's like 40,000 Milky Way galaxies lined end-to-end. The only problem? Theory says the quasar cluster is too big to exist. Astronomer Gerard Williger and reporter Ron Cowen discuss this cosmological oddity, and other news about the cosmos.
Support the news
More NPR or Explore Audio.