Researchers at MIT suggest that the microscopic "primordial black holes" could be blasting through our solar system at least once a decade.
Although our Universe may seem stable, having existed for a whopping 13.7 billion years, several experiments suggest that it is at risk - walking on the edge of a very dangerous cliff.
It is thought that the upper mass limit for galactic black holes is around 100 billion solar masses, but new research suggests the mass limit could be much higher - more than a million times greater than the largest galactic black holes.
Astronomers are studying black holes that could have formed in the early universe, before stars and galaxies were born. Such primordial black holes (PBHs) could account for all or part of dark matter.
