Jan. 29, 2020

Scientists have discovered the oldest solid material ever found on the Earth, in the form of stardust trapped inside a meteorite that crashed into Australia 50 years ago and predates the formation of our solar system.


  • This stardust provides evidence for a ‘baby boom’ of new stars that formed 7 billion years ago, contrary to the theory that star formation happens at a steady, constant rate. The materials the researchers examined are called presolar grains.

  • Presolar grains are interstellar solid matter in the form of tiny solid grains that originated at a time before the Sun was formed. Presolar stardust grains formed within outflowing and cooling gases from earlier presolar stars.

  • These bits of stardust became trapped in meteorites where they remained unchanged for billions of years, making them capsules of the cosmic time before the solar system.

  • However, presolar grains are very tiny and rare, found only in about five per cent of meteorites that have fallen to the Earth. Since presolar grains are formed when a star dies, they can tell us about the history of stars.