The Search for Positronium - Universe Today
If you could look into the sky with gamma ray eyes, you'd see gamma ray bursts, and other sources of gamma radiation across the night sky. If you could fine tune your eyes to only see a very specific colour of gamma rays, the one associated with the annihilation of matter and antimatter, you'd see wash of energy, but not coming from any specific location. Astronomers using the European Space Agency's INTEGRAL space telescope have developed one of the best pictures yet of this exotic energy.