Comment by sigmoid10

And it's still grasping at straws. The idea of a PBH as planet 9 itself is somewhat sound, but this particular paper assumes not just a significant population of MACHO dark matter, but also an additional WIMP-like particle DM that would produce a detectable signal. Is it theoretically possible? Yes. Would it be amazing to find evidence for it? Of course. Is it likely to happen? No. And we probably won't get a conclusive answer to this either way until we can easily send probes outside the solar system or at least have enormous telescopes on the moon's surface. Until then this topic is mostly an easy path to publishing papers to get tenure.