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My wife and I are working together to create a fantasy setting. In our setting we wanted the source of magic to be this magical ore similar to uranium. What we were thinking was that in the primordial time an astral entity, containing the magical ore, collided with the planet in its infancy. The aftermath would cause two types of debris to be trapped in the planet's orbit. The first would mostly consist of the planet's resources, but the second would be a smaller chunk of magical ore.
Our question to the community is could the small chunk of magical ore be captured in the moon's orbit and thus rotate around it? Keep in mind that we're thinking of keeping the setting fairly similar to the Earth in terms of physics and nature. The exception being the magical ore.