Found: Proof That Seafloor Bacteria Ate Radioactive Supernova Dust
Ka-boom! The supernova remnant Cassiopeia A, a star that blew up about 300 years ago. NASA Microbes on the ocean bottom ate iron forged in the heart of a dying star The late Carl Sagan said it best on his TV show Cosmos: "We're made of star-stuff." He meant that atoms which make up our bodies-and everything around us-formed when giant stars blew up billions of years ago. That material shot across space, clumped into the solar system, and led to life on Earth. Now a group of German scientists have gone meta on Sagan. In cores of sediment drilled from the Pacific Ocean bottom, the researchers found traces of iron-60. It's a heavier isotope of iron forged only by supernovas and mostly vanishes in a couple dozen million years. What's more, they found the iron-60 inside 2.2-million-year-old bacteria organs called magnetosomes, which the microbes use to sense the Earth's magnetic field. The half-life...