As far as we know, there likely isn't any, at least not in a persistent large-volume amount. Antimatter particles are continually created by high-energy collisi

As far as we know, there likely isn't any, at least not in a persistent large-volume amount. Antimatter particles are continually created by high-energy collisions of regular matter particles, but annihilate quickly. Cosmology speculates some miniscule imbalance in the ratio of baryons to antibaryons shortly after the Big Bang, the cause of which we don't know, is the only reason anything material exists in the modern universe at all. Most particles annihilated with their corresponding antiparticles, but there were somewhat more baryons that survived because no antibaryons remained to annihilate with, and those became all of the galactic structure we're familiar with, see, and are made of. No antimatter should have remained. More is always produced, but it annihilates well before having any opportunity to become macro-scale structure of its own.