News

  1. Earth

    A late arrival for platinum and gold?

    An extraterrestrial source may explain why Earth's mantle holds more platinum, gold, and certain other elements than it should.

    By Jessica Gorman
  2. Earth

    Strange crystal birth found in mine

    Deep in a Wisconsin mine, researchers have uncovered a new way for crystals to grow in nature.

    By Jessica Gorman
  3. Health & Medicine

    Old polio vaccine free of HIV, SIV

    Three laboratories analyzing remaining samples of polio vaccine used in the late 1950s find that none contains any human or simian immunodeficiency virus, or chimpanzee DNA—making polio vaccine unlikely to be the cause of the initial HIV outbreak in central Africa.