Could a distant Galaxy consist of Anti-matter?
It is unlikely that whole galaxies are made up of anti-matter alone. However, in the distant parts of the Universe, it is possible that some galaxies contain large amounts of anti-matter. This is likely to be caused by the cosmic inflation of the early Universe. It would not take much of an imbalance of matter/anti-matter pairs in the early Universe (only about one extra matter particle per billion pairs) to produce the situation that we currently observe. Had it been the other way round, we would now be living in an anti-matter Universe, but to us, things would seem the same. Actually, NASA is currently trying to find out if anti-matter exists in large quantities in the depths of space by looking for various signatures such as gamma rays and X-rays. Anti-matter has been created on Earth both at Fermilab and CERN, though in minute quantities, where they produced anti-hydrogen.
