Wow, we have discovered 10 anti-helium nuclei above the Earth's atmosphere in a relatively short period of time is very weird and probably significant. Even the individual particles of antimatter are extremely rare and under most conditions extremely short lived. Being able to fuse them together into a more complicated nucleus like helium is going to be exponentially harder and rarer. The normal pathways we know to produce that should happen very rarely in the general universe. Either antimatter production of protons and neutrons that then have just the right amount of energy to fuse, or highly energetic large nuclei slamming into one another, producing matter-antimatter pairs and the antimatter particles coming together and somehow escaping the nuclear collision without colliding into any matter particles. Maybe high energy protons slamming into heavier nuclei creating enough energy for antimatter production and confinement for fusion.
All of these seem like extremely rare events to me, though calculating the actual numbers would be very difficult and is beyond me. Conceivably, it could be the product of the decay of primordial black holes, but I would expect us to have found other signs, noticeable black body explosions. I'm kind of wondering if we're looking at some new physics here. Supposedly, there are some dark matter theories that predict these sorts of events would happen in the decay pathways of dark matter. I don't know anything about them.
We can get some idea of what's going on by doing the same experiment deeper out in space and seeing how it affects the rate of detection of anti helium. If it drops down a lot, then it's probably the cosmic rays striking her upper atmosphere and doing things we don't really expect them to do but it's a relatively mundane phenomena. If the rate stays the same or increases then the anti helium is likely being produced somewhere else and traveling to our space station. This would indicate a more exotic mechanism, and be a very interesting finding. I think we need to put up a gamma ray scintillator to see if we see gamma rays at the energies we would expect to see from antihelium nuclei getting annihilated.
So far, I think this is the coolest finding that we've gotten out of the International Space Station.