“If Oumuamua is indeed dense macroscopic dark matter, then we would expect that its passage close to Mercury, the Earth and Moon would have had measurable gravitational effects on their orbits,” the team writes. “Such displacements should be detectable.”
It’s an interesting theory, but probably not one that’s going to be readily accepted any time soon. We don’t even have proof of the existence of dark matter, let alone macroscopic dark matter.
“The existence of macroscopic dark matter in asteroids in general and Oumuamua specifically remains hypothetical at the moment,” Andreas Hein from the Technical University of Munich, who was not involved in the paper, told IFLScience. “There doesn't seem to be much evidence for its existence in these objects.”
Nonetheless, the idea that we can actually prove the theory true or not is interesting. Starkman noted that the researchers were not planning to do the measurements themselves, but expected them to be done elsewhere.
“This is, as the authors admit, an unlikely possibility due to the constraints we have on the density of dark matter,” Marshall Eubanks, CEO of the company Asteroid Initiatives, told IFScience. “But it would be easy for the US spacecraft tracking networks to check, and I have already encouraged them to do so.”
Well, looks like some of them have checked at the very least. Davide Farnocchia from NASA's Center for Near-Earth Object Studies (CNEOS) was a bit more scathing in his reply to us.
“This paper seems highly speculative and, as far as I can tell, has neither been peer reviewed nor submitted to any scientific journal,” he said. “We do not see any significant perturbations on any of the planets, especially the Earth.”