Notebook

  1. Animals

    Ants don’t make decisions on the move

    Worker ants stand still while processing environmental cues and planning their next moves, a new study suggests.

    By Sarah Schwartz
  2. Astronomy

    Clues left at a galactic hit-and-run

    Scientists may have discovered a dwarf galaxy that triggered a “galaxy quake” when it buzzed by the Milky Way a few hundred million years ago.

    By Andrew Grant
  3. Paleontology

    Fossils provide link in dino crest evolution

    Fossils from a newly identified duck-billed dinosaur in Montana could explain how their descendants developed flamboyant nose crests.

    By Helen Thompson
  4. Earth

    Succession of satellites keep eye on Earth

    50 years after plans were laid for the first Earth-observing spacecraft, the youngest Landsat satellites are still flying and imaging the planet’s surface.