News

  1. Archaeology

    Pueblo traded for chocolate big-time

    New evidence of ancient Pueblo cacao drinking feeds a theory of long-distance trade.

    By Bruce Bower
  2. Humans

    Record ozone thinning looms in Arctic

    Depletion could expose the northern midlatitudes to higher-than-normal ultraviolet radiation in coming weeks.

    By Janet Raloff
  3. Earth

    Cave formations record Black Sea deluges

    Stalagmites in a Turkish grotto document 670,000 years of flooding.

    By Daniel Strain
  4. Astronomy

    New study gives dark energy a boost

    Measurements provide further evidence for a cosmic push that is accelerating the expansion of the universe.

    By Ron Cowen
  5. Earth

    Japan quake location a surprise

    Based on regional tectonics, seismologists expected the biggest events in the island's southern half.