You cannot see the object, remember? How can you predict something which you cannot see by some means? Unless you have a high-powered infrared or x-ray telescope, I doubt you can verify it's very existence in 100% certainty, and must therefore accept the possibility that this cosmological anomaly does, in fact, require the earth to be round.
Especially when we can observe the other heavenly bodies such as Jupiter and Saturn eclipsing their own moons quiet often (and the fact that FE-ism states that the other planets and moons can be/are round).
I'm just testing your belief in this dark object and seeing if you can, logically and coherently, prove that it 100% exists.