KNOWLEDGE of the abundance of antiprotons in cosmic rays and in interstellar space could have important implications for cosmic ray theory, γ-ray astronomy and certain cosmological theories.

On a similar note, many dark-matter candidates are predicted to produce more cosmic-ray antiprotons than are observed if the annihilation rate is normalized to the electron and positron signals ...

Just as it's possible to squeeze out a fine mist of antimatter using particle colliders here on Earth, nature continues to shed antiprotons and antineutrons in cataclysmic high-energy events.